Was just about to sharpen up a Schmachtenberg I picked up off the bay a while back, and the scales came apart. (pinned on one end, glued on the other)

Does anybody know what kind of glue was used to put this type of scale together? hide glue? or similar furniture glues?

What would be the best bet for reassembly? I can imagine that some glues work better on Bakelite or celluloid than others, and some might become a nightmare if there was ever a desire to seperate the halves again.

Thoughts?