Hi
Really nice work. I did a similar project, natural finish with Tru-Oil using slurry method.
This link may be useful for sourcing a bridge https://www.twojah.com/parts-and-accessories/bridges/musicman-sterling-bridge-4-string
Indonesian based - I ordered a G&L one for my project. Postage is expensive at around $40 - Didn't know if site looked legit but came through and the guy (Eben) is really helpful.
Good luck with the finish ...
Oh and when it comes to contouring the body .. Shinto Saw Rasp ... amazing bit of kit.