Antique Ruth & Boaz Cameo| What should remounting do or not do?

by Jeanie
(Portland, Oregon)

Mom gave me a cameo last summer. She said was over 100 years old when she got it almost 20 or 30 years ago. I'd like to wear it but it's fallen out of the mounting (brass with a t-bar) and the mounting has clearly seen better days. What should I look for in a jewelry repair person? It has XII marked at the top and dh (?) or a up (?) on the back. The topic is Ruth and Boaz.