Repair manuals for Mamiyas aren't very good regardless of where you get em from. I have the origianl sets n they aren't worth the paper they were printed on. Pictures aren't very good, text is translated Japaneese to English by a guy that took the Bill Murry English course.
What I used em for was part numbers n ordering from Mamiya. Now that those days are gonce, you just buy broken cameras n swap parts to make one work.
With the build of these beasts, they generally don't need repairs or parts, just adjustments that are intuative. Delrin rollers can't be ordered anymore so you'll have to make some parts. With enough exposure to the insides of these cameras, you can basically know what to adjust since they have so many places to make adjustments.
Backs take a bit more technical knowhow n the manuals have some tips of adjsutment points but not very reliable as there are so many versions of each. Most of the backs that I get to repair have been very heavily (ab)used n are beyond repair. Most of the amature cameras are the abused ones. Cracked castings form snapping the advace lever, broken springs because the back hasn't been serviced in a long timen they are forced, amatures don't care for their equipemnt since high maintenance cost is a factor. A few just need adjustments but these are rare n come from well taken care of cameras, used mostly by pros n amatures that love their cameras n have routine maintenance done.
Lens manuals, pretty much don't exist. Shutters weren't fixed by Mamiya, they were replaced. Pro shops did some repairs at the mercy of parts availability form Mamiya. You got exploded views of the shutters n went by that for some parts they may have on hand. There were a few people that made names in the business specializing in em but charged handsomly for the service, mostly LF equipment repairmen. I did n still do as long as they come out of older lenses n the parts it needs aren't too hard to find in my closet of broken shutters. Then Mamiyas went to stamped steel shutters n pinned moduels, with fewer replaceables, n now in the newer lenses, plastics that make em tossers.
So instead of buying manuals, buy a broken camera, open em up n compare working ones using your mechanical skills to figure out the problems.
I've found nearly every other Mamiya manual online but not repair manuals.
