@indigomoth - I hope they aren't modifying real Victorian jewelry!
Not only is it very expensive, but the handmade pieces should be considered works of art. I hate to think of someone gluing extra bits onto someone else's work of art, even if the artist is dead.
And there are so many people interested in buying authentic old jewelry. There are plenty of replications available for modifying if people must do that.
I guess I have a few pieces of Victorian enamel jewelry that I would never try to change, so I'm a little bit touchy on the subject.