Just to bring closure to this thread, I now have the ring in hand (thanks Cecil), and a quick peek with my loupe solved the mystery. The two stamps on the outer ring shank are German export/Swedish Import stamps. The oval with 3 crowns indicates Sweden, and the S in a hexagon indicates a silver purity of at least .800 fineness. Since Sweden and Germany kept up a lively trade of goods throughout the war, this was exported by the maker to the Swedish market. Thanks for putting me on the right path with your suggestion, Odal!
