A pink gold open-faced quarter repeating musical watch, unsigned circa 1820

18k, gilt full plate verge movement, fusee and chain, plain brass three arm balance, repeating on two gongs, playing on a disc with 20 tines, the music bridge engraved Valtz no. 86, gilt cuvette, white enamel dial, Arabic numerals, outer minute track, the case back engraved with musical instruments, reeded band.