Well, huge difference between just an 8x10 back and a C-1 8x10 back.
I have a wood 8x10 back that's probably from a b&j or old eastman, not sure because its on a custom junker p&s.
I also have a c-1 but I'd never part with my 8x10 back from it, and doubt many people would.
If you'd want it, I could probably rework that wood back to fit a c-1, need to measure and if it looks like it could be done it would be a half day worth of work or more. Let me know by pm.
If you end up with a parts camera I am looking for a rear carrier and the part which mates to the top of the rear carrier for a project I have. I don't need the rear side standards, frame or back. Again please let me know via pm, I'm only on apug about once in an average week and might not see a response here. I'll cc your email too.