Vintage Happy Birthday Sterling Silver Charm on Card

Sweet vintage sterling silver Happy Birthday floral charm, never used or even removed from its card. It measures 3/4" in diameter and is marked on back "Sterling" with a makers mark that looks like an S. Charm is in excellent condition but card backing has a little paper damage at top left and is a bit short -- looks like the bottom might have had a price on it, and was detached along perforation.