Silver abalone, onyx hinged bangle bracelet vintage ll2403

This bracelet is probably either silver plated or Alpaca silver which is not really silver at all. I'm leaning toward plated as there is wear on the inside of the bracelet typical of worn silverplate. The outside looks great with no damage to the stones or wear to the silver. The inside circumference is 7.5 inches.

The inlay includes abalone, onyx and a red and a white I'm not sure of. The bracelet is marked but it is worn down.