Here's a beauty I recently ran across that might be of some interest here. It's a great player and has some elegant features like the inlayed wood frets and pretty fancy tuners. I gave these the old archaeologist's "tooth test" and, while the thumb pegs is certainly celluloid, the four tuners in the peg head tap against the teeth like bone.
Interesting Note: the inside of the rim appears to have been signed in black ink early on. There are four or five words present; the only one still legible reads Bishop.