Swiss. A rare and attractive 18K gold and enamel s-form pendant watch

Swiss. A rare and attractive 18K gold and enamel s-form pendant watch
Unsigned, movement no. 4990, circa 1820
Gilt-finished verge movement, chain fusée, white enamel dial, Breguet numerals, hinged within the circular case with translucent blue enamel decorated domed sides over bark-finish background, centred by a white enamel stylised flower, white enamel stripe decorated outer border in the shape of the letter S, short length of pink gold chain with white enamel letters ouvenir, the whole forming the word Souvenir, suspended from a short length of gold chain, unsigned
39 mm. overall length