Th watch has the gold hallmarks of London assay office from 1935. But it has also the Swiss 'Poincon de Maitre 'the hammer with the handle which was used until 1934. This means that the watch was in early to mid 1930s, 1933 or '34 precisely. It was cased in Switzerland, and later exported to Britain where it had to be controlled and stamped for it's finesse of 18k gold and hallmarked. Obviously it has been hallmarked in London in 1935 and high probably retailed there. It has engraving on the back.