An antique early 20th-century open-face pocket watch by Paul Ditisheim. Smooth sterling silver case with blue enamel accent. White enamel dial with Arabic numerals and sub-dial, marked Paul Ditisheim, Solvil. Marks on the inside: HF, Swiss bear mark, 0.925, German crescent and moon mark, Solvil, 308920, 748973. Paul Ditisheim, 1868 to 1945, was a Swiss watchmaker who established the Solvil et Titus watch company in 1887 and ran it until 1930. Collectible Clocks And Watches.