VINTAGE GOLDTONE HEART PENDANT NECKLACE W/INTERCHANGEABLE CENTER HEARTS-"W" MARK

Very attractive vintage goldtone heart pendant necklace with four interchangeable center hearts. The necklace features a "W" mark on the back of the pendant, and though I tried to research this mark, I couldn't confirm who used it. I believe the interchangeable hearts are made of glass (they are not plastic, and I don't believe that they are genuine gemstones). The center hearts are gold, garnet red, dark green, and black, and have magnetic backs. You remove / exchange the center hearts by pushing them out with a pin, or needle, through a small hole (designed for this purpose), on the back of the main heart. The chain neasures 30", and has as a lobster claw clasp. The heart pendant measures 1 1/2", top to bottom, including the bail. It is approximately 1 1/3" wide. The center, interchangeable, hearts are 1/2", in each direction. This necklace is in terrific vintage condition with minimal, if any, wear.