My father, who just turned 79, worked for Fender in Fullerton back in the 60's. He was in the electronics R&D group. He got a 1960 Fender Jazz Bass and has had it ever since. He was under the impression it was a prototype, but with the dates on the neck and pots and the serial that seems unlikely. We do know it wasn't refinished, but the neck cavity/pocket is painted black (I attached a photo). Some think this is a sign of refinishing. I'm looking for information on other ways to identify/prove original vs. refin paint. Any and all opinions are welcome!