Hi Sinsull, this sounds like a job for the experts. If you were in Australia I would refer you to the National Sound Archives in Canberra (it now has a fancier name).

In days gone by skilled operators could do minor micro-surgery through a microscope on the vinyl/bakelite grooves. I read about this years ago in a copy of Audio.

Since that time I've also read that computer guided lasers can now track the grooves without physically having to interfere with the record itself. There's an Australian guy who has performed absolute miracles on old 78's for our Government owned ABC, but I suspect that he concentrated mainly on dramatically restoring the music content as opposed to allowing the record to track properly. I'll wait for some further responses geographically closer to you. Regards, John