Okay I see, too difficult and too few hints.
Solution: Mamiya 7 80f4 lens on Alpa FPS (and IQ180) via customized shift adapter
Mamiya 7 lenses are always praised for their sharpness on 6x7 film, since some time I had the plan to try to mount them onto my FPS to see how they would work with a 645 size digital back.
First thing was to find out the exact flange distance to determine how much space there would be for a mount mechanism to the FPS. Luckily the head engineer of Mamiya Germany camera service in Munich was very helpful: it's 57,85 mm. Then I purchased a 6.5mm distance frame from Alpa for the FPS because my idea was to use the side rails directly for the shift mechanism of my lens mount. The whole mount is machined from a single POM (black plastic) block. From Mamiya Germany I got a Mamiya 7 camera spare part bayonet ring which I screwed on the front of the shift mount.
I searched for second hand Mamiya 7 lenses and found four nice lenses in very good condition for reasonable prices: 43f4.5, 65f4, 80f4, 150f4.5
Due to the fact that the Mamiya 7 is a rangefinder camera, the lenses have no spring loaded apertures, so the aperture ring is directly coupled to the aperture blades.
The main problem to solve was, that the Mamiya 7 lenses contain electro-magnetic central shutters which are closed without operation with the camera. Again the friendly Mamiya service was very helpful: They disassembled the lenses, removed the shutter blades and reassembled the lenses. During that proceedure we decided to leave away some "unnecessary" parts: the rear tubes of the 43 and 65 mm lenses because they restrict the shift movement and all prominent levers that stick out at the back side of the lenses because obviously nothing is coupled to the FPS camera.
After first assembly of the shift lens mount on the FPS I found out that infinity focus could not achieved: the lens mount was 1,5mm too wide. Why? Because Mamiya defines a different flange at the mount for the flange mount distance than assumed by myself. Okay, some re-machining, then the set-up worked fine.
The 43 mm lens allows about 6-7 mm sidewards shift until the back lens barrel interferes with the inside box of the FPS, the 65, 80 and 150 mm lenses can be shifted up to 13mm left and right until light would leap in between the Alpa 6.5mm frame and the shift mount.
Of course the lens mount can be turned by 90° to achieve vertical shifts.
The 65 shows little, the 43 some color cast towards the edges. I have to do some white panel compensation shots to see how severe the effect is.
Sharpness of all lenses look very promising, more test pictures to come.