Hi, I have never been able to purchase a zorki or fed at a sensible price, so have never dismantled one to see the difference between the shutter assembly..
However, from pictures, the drum looks identical. If it is, then most of the work has already been done.
The zenit/zorki/fed were all derived from the stolen Leica design.
I took a working shutter mech from an early zenit and used this for all the measurements and spacings.
It is critical both parts of the drum are aligned correctly and the distance from the drum to each of the curtain laths is correct.
It will require somebody to print the Zenit jig & see what parts align correctly with zorki/fed/leica shutter curtains.
Alternate is to send me some free cameras
)