Distributor repair

I have a couple of the MP mechanical tach drive electronic distys (PN 4120701) that need repair. One has something wrong with the tach drive mechanism (tach drive rotates freely), and the other has a problem with the mechanical advance mechanism. (doesn't seem to advance correctly). I just put in a third one of these from my junk box that works just fine.

Anybody know a place that can repair these, or are they throw away?

If no, I might be able to tear both apart and make one working unit.......