I've looked high-and-low for a few years...hoping to find someone publishing detailed conversion procedures.Anyone know if the Mamiya RZ 67 220 film back can be converted to 120?
No Joy! As others state, buy a 120 back or a 120 insert.
Keep in mind though, original Pro inserts only work in original Pro magazines/housings.
Original Pro backs used light seal material.
Pro II inserts only work in Pro II backs.
Pro II backs employ a light-trap design, or remolding of the seal areas...no seals required.
No inter mixing of parts allowed between the original Pro and Pro II backs,
except for...dark slides and plastic storage caps are the same between the two series of backs.