I work at a music store doing the guitar and bass stuff. I'm working with these instruments a lot. When there is any problem besides intonation, restrings, or setups, i generally send it to the other store. Im learning how to solder, so thats not much of a worry. But say, replacing pickups and tuners and bridges. Making new nuts. Shimming necks. You know, repair work...are there any good books out there that teach this stuff?