Abalone Sterling Silver Pin & Pendant retailer

This vintage 2 inch in diameter abalone sterling silver pin can double as a pendant due to the loop on the back. Please see the pictures for a closer view retailer. It came out of an estate in Maine and is a beautiful piece. The other piece, also listed on this site, is a little older, however we are fairly certain this piece dates back at least to the 1950's. It is gorgeous and signed by the maker. We are unable to exactly define who the maker was. A classic design and considering age, in great condition.