A lady's diamond wrist watch

A lady's diamond wrist watch, 1920s and later, the silvered dial of Art Nouveau inspiration with black enamel numerals and blued steel hands, to a platinum case millegrain-set with single-cut diamonds, the sides with laurel leaf borders, to a later 9ct white gold mesh link strap, dial 16 x 15cm, watch back with Swiss assay mark for platinum, watch strap with British hallmark for 9ct white gold, date letter for 1963