So, I just ordered one after all; an adapter in order to connect between Fujifilm GFX camera, and Mamiya RZ67 lenses. Albeit nothing sophisticated.
Just the American Fotodiox version, made for Mamiya RZ/RB Sekor lenses (from Mamiya RZ67 and RB67 studio cameras) - which now can be adapted to the Fujifilm GFX digital "mini" mediumformat camera, with help of a built-in helicoid focus.

Since the Mamiya RZ/RB lenses themselves have no helicoid focus built-in - you can't really set any focus (the Mamiya RZ/RB system uses built-in bellows in order to obtain focus). That's where the helicoid adapter comes into play with this Fotodiox RZ/RB adapter.
An alternative would be a bellow-adapter, like from Arca Swiss (?) or Novoflex. Albeit those solutions are so much more expensive - albeit more flexible, too (with shift/tilt)

Not exactly same adapter, but is showing the same proportions; Mamiya Z 180mm lens + adapter & Fujifilm GFX camera
4000 SEK / 353 €
Since I bought it in Sweden for 4000 SEK, it was surprisingly at a lower price compared to other alternatives. Like ordering directly at the Fotodiox US company ($274) but with frikking high shipping costs + additional import costs and finally the sweet cherry of Swedish 25% tax. Resulting into something like 5200 SEK. (Puh!)
No thanks. 
In Germany one store had it for 375 € with 19% German tax - but that is exchanged into Swedish 25% tax, due to the internet sale rules of the totalitarian EU territory; also making it much more expensive = 4600 SEK.
If I dislike it - i can send it back within 14 days - and get my money back.

A user photo shown at B&H with the Mamiya D/L 180mm Soft Lens, adapted to the Fujifilm GFX
Vertical/horizontal camera position issue

I assume that this adapter has a fixed horizontal mounting position.
With help of a really huge L-grip (horizontal + vertical) i could adapt a Manfrotto tripod plate on each side - and then simply switch the camera between vertical and horizontal position. That way the whole equipage and weight will remain centered over the tripod head.
Leaning the camera + lens to the side by 90° in order to take vertical images would be rather cumbersome - and possibly even dangerous due to the vast weight shift to one side. Mamiya RZ67 lenses ain't light weight !! You can see how large they can be in the image above.
Straight adapter only

In this case, we are talking about a "straight adapter"; meaning that the Fujifilm GFX with its 33x44mm sensor only utilizes the center portion of the 6x7 mediumformat lenses. Never the borders.
About Mamiya lenses on a digital sensor
I know already that most Mamiya RZ67 lenses are on the soft side, when used at wide open aperture. They will show chromatic aberrations, as well. But once you stop them down, they should turn out sharp, and with little or no chromatic aberrations.
ULD, L-A and APO lenses will fare best, because those have been refreshed when Mamiya started with digital backs (Mamiya RZ67 II-D) as professional photographers required better lenses. (image sensor are far more picky). Which Mamiya addressed with some refreshed lenses.
No need for pimped "digital" Mamiya RZ67 lenses, really
For film usage however - you will not see any difference (or just barely, if at all). You honestly don't need any of those more expensive lens version, unless you use them digitally. For film - the normal (original) versions all perform super well !
That's what they got known for in the first place; for their high optical quality.
I will not buy any "for digital improved" versions - because they all fall outside of what I use, need and consider useful.
There is the wideangle Mamiya Sekor Z 50mm ƒ4.5 ULD, the Mamiya Sekor Z 65mm ƒ4 L-A lens. (i have both the normal versions). Nor the Mamiya APO Sekor Z 250mm ƒ 4.5 or the Mamiya APO Sekor Z 350mm ƒ 5.6 (again, i have the normal versions already).
The only APO lens I have is the Mamiya APO Sekor Z 210mm ƒ4.5 lens. It is excellent on film - perhaps slightly on the harsh side, and extremely sharp ! While also being the most affordable among the four APO lenses.
What about the Helicoid in the RZ-GFX adapter ?

Now the question is; how far does the Fotodiox RZ/RB helicoid adapter extend ?
Good question.
I honestly don't know.
It is surprising that I never found any numbers - at all. Also surprising is that so few forum members (those who own the adapter) never even mentioned any details, the practical stuff, etc, I mean. Plus that it is almost impossible to find anything if you use/ask Google or DuckDuckGo... It is just a lame duck, at all levels.
Maybe questioning AI would be a better idea - albeit they sometimes can lie, too.
In case extension is limited...
Now, let's say the extension helicoid is too small, and I don't even get close in any way. Then, i can add a Mamiya extension tube No1 with 45mm extension. That certainly is good for anything that is close. Not macro, but a lot closer. (i often use these extension tubes with Pentax 67 lenses, too).
No a problem, but rather fun to "fiddle" around. After all - it extends a lens - and I love that.
I expect the Fotodiox RZ/RB adapter to extend perhaps 25mm or 30mm at the most. Which should be enough to cover the basics to get close-ish. Otherwise i use the 45mm extension ring. Problem solved.
There is also another Mamiya RZ extension tube No2 (very affordable, too), which I believe is whopping 82mm. That's however likely too much for me.
I don't intend to do real macro with Mamiya RZ lenses + Fujifilm GFX. I use other combinations; either the Sigma ART 70/2.8 Macro + Fujifilm GFX, or the extremely flexible, simply formidable Olympus OM-1 + M.Zuiko ED 90mm ƒ3.5 IS Macro lens (and/or the M.Zuiko ED 60mm ƒ2.8 macro, works wonderful, too)
Optical quality in the closest range (with non-floating elements)
The normal Mamiya Sekor Z lenses are not really made for strong close ups or macro.
You can do it - absolutely yes - - but if you want sharpness - you need to stop those lenses several stops down in aperture, in order to obtain a better sharpness. Otherwise you'll see fuzzy details if you work with wide open aperture or stop only 1 stop.
Like most lenses from the film era - they perform less sharp in the closest range. I mean lenses that didn't have "floating elements" inside. The latter are changing position when going really close, in order to counteract the optical degradation that normally causes. Most lenses were optically calculated to bring out their best when the focus was further away until infinity. But would drop in performance when going really close.
Macro lenses on the other hand, where optically designed the other way around; they performed their best in the closest range, and not always equivalent good at infinity.
Leica lenses from the film era in the 70s and 80s, under-perform optically when you get closer than what they were designed for. But even when you got close to their minimum focus distance, they started to drop. They often stopped at 1 meter, while others at 70cm.
The price story of Mamiya RZ67 lenses through time
The Mamiya RZ67 and RB67 lenses are pretty cheap today - because you can't do anything with them - other than putting them onto the big, heavy, analog camera they were designed for. Without helicoid focus, these lenses make no sense to people. Few ever see meaning in adapting them to a digital camera. Mamiya also has no particularly wide lens; the widest straight drawing lens is 50 mm. Wide on a Mamiya RZ67 camera, but corresponds to a nearly normal focal length on a digital camera. So, people see no use in using those big, bulky lenses.
Understandably so.
That is the reason, why Mamiya RZ67 lenses are among the cheapest mediumformat lenses available out there. Followed by Bronica and then Pentax 6x7 lenses. Hasselblad Carl Zeiss go for quite a bit higher prices. And so on.
They made everything themselves
Mamiya didn't only mold their own lens elements, they even made and mixed the glass types from scratch themselves (!!) It is a telling story of the high very high quality and know-how behind those lenses. Right from the start when Mamiya introduced the electronic version of the Mamiya RB67 in the early 80s.
The Mamiya RB67 was already big name among portrait- and wedding studio photographers in the 70s. The RZ67 would bring it even further into the world of fashion and product photography world wide. It was a camera ground-solid straight from the beginning, very flexible - and is so even all the way today in year 2025. These cameras hold up.
A remarkable feat.
3 lenses = Enough for a mediumformat film camera
Yet, three lenses covered all the basics one could think of. When you owned a medium format camera; the rule was simple: a wide lens, a normal and a telephoto lens. With 3 lenses, you would conquer the world. It did really cover the most, and basically all that what was important. As it was simple. Not having to chase and yearn for more lenses. There was no "new" or better "version". They were already perfect. The negative format with 6x7 cm was so large compared to the 35mm film (24x36 mm negative), that you could make very large prints in high quality, great sharpness and very little grain.
It was heaven !
Second hand market, much lower prices

It wasn't until the early 2010s when i started to buy Mamiya Sekor Z lenses again (as well Mamiya C330 lenses) The company itself was gone by 2015. Second hand prices had started to fall, more significantly in the latter 2000s, and fell even further during the 2010s.
I bought many !
Oh boy, I bought many... Must be a boy-thing from when i was in my early 20s. And the more Mamiya Sekor Z lenses i bought during 2010-2017, the fewer i used the camera system.
Another weird development.
A real surprise...

One lens startled me totally: The Mamiya Sekor Z 100-200mm ƒ5.2 ZOOM.
So dirt cheap - and still is - where i paid something like $100. The optical performance was and is simply stellar. I really didn't know what to think of that lens when i decided to buy it - until i tested it on Sal in Aug 2017 - the year we got married.
And boy - it was good. As good as the fixed lenses.
Good optical performance in a ways that baffled me. Probably because I never expected that. I mean a mediumformat-zoom lens from the 80s (?)...
I bought the lens because it was so damn affordable - and I wanted to know why. (i had heard mixed results, but nothing precise). For the low price, i thought - OK, why not. Let's test it. Well, it was beyond all expectations (outdoors).
By the way - it is the only zoom lens in the Mamiya RZ67 lens line-up.
The question is however - does one really need it ? Here is the thing: It comes with a LOT of weight attached, and a special lens holder is recommended to be used on the RZ67 camera, in order not to bend the built-in bellow mechanism. The Zoom is heavy, and it is long - similar to that of a 350/360mm Sekor Z lens.
So, it ain't a little bird exactly.
"It's so big, that it has its own zip-code" 
Moving forward to today
The Mamiya Sekor Z 65mm L-A has increased in price due to the floating lens elements I am sure, but even more so the Mamiya RZ 50mm ULD, with a doubled price now around 900€ at the lowest. Probably because of the excellent quality with digital sensors. Albeit with film negative,s you do not really need any APO nor ULD lenses. The reason is that it isn't really visible. Only on digital cameras - that's why Mamiya renewed some lenses, with floating lens elements, as well some APO lenses, so that photographers with digital backs on their Mamiya RZ67 II-D cameras, would get the best quality of the newer, refined lenses.
But for film use, none of the renewed lens version are necessary other than you spend a lot more money. For example - the ordinary Sekor Z 50 mm ƒ 4.5 lens wideangle lens, is as good as it can be. People didn't seen any difference in the corner performance with the "better" ULD version.
Because it isn't visible on film negatives.
Mamiya Fish-eye Sekor Z 38mm ƒ4.5
has gone up by factor 5x and more (1500 to 2700 €). For the clean ones, not hazy ones, of course. That the prices have taken off that much surprises me, given that Fisheye lenses are iffy at best. I bought mine in 2013 for 400 €.
Sure the Mamiya RZ version is better than the Pentax 67 version, i can assure you that, because i have both. Albeit i used the Mamiya Fisheye with film, while the Pentax Fisheye with 7x7 cm digital emulated sensor. The latter was severely fringing with vast amounts of chromatic aberrations and blurry borders (albeit the center was fine). It might not be as bad when using it with black & white film instead.
Giant Mamiya APO Sekor Z 500mm ƒ6

The APO lenses on the other hand, are still pretty affordable and maybe have reached their lowest price point ever, including the monster APO 500mm ƒ6. But that one is so incredible large, long and heavy (APO lenses are generally because the special glass elements used are heavier than normal). And you need a special lens-holder made for it ! Those unworldly large lenses never got popular. Those Minds who bought it when it got affordable - perhaps due to a childhood dream - but sold them off again.
Which is understandable. I mean, who walks a lot around with such Mamiya RZ67 monster lens - while pulling off some truly stunning photography ? One in 100 million, perhaps.
Have you even really seen any images ever made with the Sekor Z 500mm lens ? It is super rare, and reminds me often of somebody just taking a few test shots - and then the thing lies somewhere in a closet.
There you have the answer.
Good hint for walking about with a Mamiya RZ67

I use a 'professional' shopping bag / roller with air filled wheels (which can take up to 50 kg): no need to carry everything on the back - ever !!! With ease you can carry with you several lenses, even the bigger ones.
It is a great addition to walk around like that in town - believe me. No problem what so ever. Just use some foam on the bottom of the roller for even more protection against bumps - and you are ready to "fly" anywhere on a buss, via subway and walking around - wherever you want to.
I love it, dearly. So practical !
Mamiya RZ67 ruled the world in Product & Fashion Photography

Mamiya RZ67 where dominating in studios revolving fashion and product photography. A camera much more flexible and effective compared to the "6x6" Swedish Hasselblad. With the 6x7 format you didn't have to cut down the image too much - but when having to do so with a quadratic 6x6 negatives - not much is left.
With the Mamiya RZ67 you could choose between 6x7 or 6x6 without loosing much of the negative area estate (dependent if a quadratic or longish format was required for print, I mean). With a pure 6x6 format, you lost a lot when there was a need for a horizontal / longish format. you ended up with 6x4.5 cm instead.
Hasselblad was more of an icon; a statement, a classic portrait camera as well often used for landscape, art and as an outdoor camera - which even could be used handheld. The "6x6" format itself is an icon, with special aesthetic qualities, I think.
The Hasselblad camera itself, was a stunning, distinct crafted beauty - relatively small compared to the bulkier Mamiya RZ67.
I think that is enough today, about Mamiya RZ67 lenses  |