@Dan Daniel the shutter is controlled via the knobs. A previous version (with Bronica 50mm f2.8) used a self-cocking shutter which was nice but required a loop of cable release.
The cam follower on the body was replaced as you can see in the pic above. It's a bit shorter than the original. I screwed a protrusion (a flat cam) on the "lens board" which translates linearly via the helicoid and contacts the roller on the cam follower.
The RF expects a 52mm lens which translates 3mm from infinity to 1m. The key is finding out how much the new lens moves for the same distance range. Then the cam on the lens or the length of the follower must compensate for the difference. The movement of a lens
f from inf to
D is approx
f2/(
D-2
f). Often the marked focal length is not exact but close enough.
This is my 6th or so pano build (check my flickr). I used mostly retrofocus lenses before and this is so much cleaner.