|Posted: Thu May 17, 2018 5:44 am Post subject:
The only source of ready-made parts for these would be other 75mm Fat Biotar lenses, such as a broken, parts copy.
But those would be rare.
The only alternative would be to make one yourself, using the other blades as a pattern. I have run across cases posted on the internet of people who have made replacement aperture and shutter blades out of various materials, one being steel shim stock.
I don't think you need to use spring steel like the originals (spring steel will last longer though) but the thickness will need to be identical or very close.
The pins can be cut from a proper guage of brass wire, and held in the blade by peening (flattening with a little hammer) as the originals were.
This would all require a bit of ability as a craftsman. Lots of filing and fitting.
I like Pentax DSLR's, Exaktas, M42 bodies of all kinds, strange and cheap Japanese lenses, and am dabbling in medium format/Speed Graphic work.