Yeah, that's where I'm headed.
Donald, I didn't realize (perhaps I read it and absorbed it subconsciously) you had posted about sawed-off plastic-body 'roids for a film back, but I did not throw away much of the several roids I gutted, and I'm glad. They have so many neat little mechanical parts I'm recycling them like crazy...springs, pivots, door locks, rangefinder and viewfinder, you name it.
I really like the EV part of them becasue it lets you disregard the weird f/numbers, or establish a new reference if you alter the focal length...like putting a Telek or equivalent behind one (with a longer back in that case). I found out most of the rollfilm 'roids have the same door dimensions, so I can swap camera fronts on a box with a metal front plate cut to fit the back door seal dimensions. I found 95B, 150, 160 & 800 all have same back dimensions. I have a long box with 5x7 filmholder ready to swap dissected 'roids onto...I just haven't figured out yet how to make the bodies detachable. They are heavy and there isn't much of a lip on that door seal to attach hardware to. Epoxy would be fine, but ruin the body swap concept.
One will be triplet + neg lens cell stretch to 210 mm and another will be bellows fron pinhole, if I can figure out a suitable mount.