Cole Haugh has a nice tool made up for removing the disc set strikers. It wasn't very expensive. He has new firing pins on hand, also. The firing pins that are original to my gun don't look as nice as Cole's, but, I left 'em in place to see how long they will run. I suspect they will be there a long time.
Good to be prepared, however.
I'm finding my stock dimensions have changed a bit over the last few years, seems like I need more cast, less LOP, and I'm more sensitive to pitch then I used to be. I'm still sorting that all out on this Uggie, and when I get it right, I think I'll put a nice leather recoil pad on the gun.
Good luck with your project, it seems like most of what was wrong was due to the wrong people owning/working on it, rather than any direct fault of the gunmaker.

Best,
Ted