Early 19th century yellow metal and enamel open face pocket watch, James Upjohn

Early 19th century yellow metal and enamel open face pocket watch, James Upjohn, New Bond Street, London, circa 1825, the white enamel Arabic dial with gilt Breguet-type hands, front cover with blue and white enamelled dentil detailing, the case verso with deep blue guilloché enamel spiralling panel enclosed with dentil decoration, 'Upjohn' signed chain fusee movement numbered '576', 47mm diameter (ex.suspension ring), 83.9g gross approx, with thin yellow metal chain and key