I found this Pocket Watch earlier this year and decided to pry off the back hinged cover. This revealed a second cover called a cuvette. My understanding is that this would be a common place for an engraving. The case was in surprisingly good shaped with gold plate still intact. Problem is there is a coating of green buildup. Some of it chipped off to reveal the gold plating underneath once again in very good shape. I think there might be an engraving underneath the crust of gook. The question is, how do I get this stuff removed enough to see the engraving? Thanks in advance for your help.