Are Voigtländer Bessa viewfinders interchangeable?

[aizan]

Since R3a and R bodies are common enough, could you swap the optics and end up with an “R2a” (which is pretty rare on the market now) and an LTM “R3m” for all of those screwmount 50mm lenses?

 

[xasthur]

I would guess you probably could? I've taken apart my R4m and I've seen other voigtlander and similar cameras to them with the top plate off and they all seem very similar if not the same but of course with the magnifications and frame lines.

This would be a very interesting project to attempt if you have the proper tools and the money for both cameras and accept the possibility of it not working at all.