Let us know how it works out.
Not well. Here is a summary.
1. Re-mounting the Mamyia 65 mm 3.5 (for the TLR) took some time. Removing the flash-sync wire required disassembly down to the shutter's core, to access the solder joint. I could have just clipped it off but wanted to preserve as much of the parts as possible.
The shutter I bought (for cheap) had very slow speeds for 1/4 to 1 sec, with the latter taking about 1 minute to close back up. After some soaking in 95 % alcohol, and working the shutter when wet, and then rinsing with naptha, the speeds came back to near normal and stayed that way.
2. The flange to film distance turned out to be quite short -- 73 mm. So I still had to mount the sliding mechanism inside the body of the camera, just as I would with the usual wide angles, such as the S-K Angulon 65 mm.
So, there is no advantage to the retro-focus design on the Busch Pressman.
3. Coverage on 6 by 7 ground glass was complete. I mounted the lens on a 4 by 5 and the circle of illumination is about 3.5 inches, or 89 mm, at f22 (not much change from f3.5 to 22). The sharpness looked good to about 3 inches. This could be enough to cover 6 by 7 (68 mm circle ) or 6 by 8, but I did not check it with an exposed negative.
4. The Mamyia's Seiko shutter does not have a T setting, or a cable release fitting, so focusing with the ground glass is awkward.
5. The Busch Pressman will not close-up with the Mamyia lens mounted. (I was anticipating this). The intact lens will screw into its retaining ring through the board, so it is easier to remove and replace that way instead of with the four tiny mounting screws.
6. The lens is very light, and
the viewing lens makes a great loupe for ground glass viewing. The eye relief and focusing distances are ideal.
7.
The Busch Pressman 2 by 3 is not wide-angle friendly. Post # 2 indicated that a wide-angle could be used, and that started me down this path with the Pressman.
8. A focusing rail could be retro-fitted into the camera body without much cost if DYI. I think it would take about as much time as taking the Mamyia lens apart and re-mounting it, once the parts are in-hand.
9. The most expedient thing to do, especially since I plan on using it for landscapes with no movements, is to just mark the infinity position on the inner rails, and use it as a fixed-focus camera most of the time.
10. Unless you have one handy, and not used for anything else,
I would not recommend using the Mamyia 65 mm f3.5 on a Busch Pressman Model C, or even on a 2 by 3 Century Graphic, because of the lack of a T-setting on the shutter, and no cable release fitting.
