What level are you looking for? I recently rebuilt a Federal pump and it was very straightforward and a pretty fun project. Lots of info on how to do it online and in the FSM. The seal kits are readily available and about $15-20. If you want to send it somewhere, Steer and Gear does them, but that’s going to be a mechanical rebuild only with no eye towards appearance. I’ve heard of a guy that does full service restos and will dig his contact info. He has a good rep as far as I know.