Source for small individual shutter repair parts

Where do the repair guys get small parts for shutters?

I find myself with 2 Seikosha shutters that are rendered un-useable because of s tripped cable release sockets. These are actually the Mamiya Universal/ Polaroi d 600SE variety that has a socket swedged into a small round holder. But other things keep coming up also where it would be nice to have a source for parts.

TIA Jim

Have you checked with a camera repair company?