Not sure if I'm putting this in the right section. My husband has inheried a napkin ring from a reltive who lived in Switzerland. He found that the hallmark suggests the Birmingham Assay Office, 1902 and the maker’s mark C.H looks as if it belongs to Charles Harrold & Co of 2 and 3, St Paul’s Square, Birmingham. That address is now a live music venue called The Jam House.