A two-tone gold rectangular jumping hour wristwatch, Rolex, Ref. 1491HS circa 1935

18k, nickel Rolex Prima Observatory quality movement with moustache lever, 15 jewels, mono-metallic compensation balance, timed to 6 positions, silvered dial, arabic numerals, aperture for jumping hour, square minute dial above large subsidiary seconds, rectangular yellow gold case with white gold flared sides, case, dial and movement signed, with an 18k gold Rolex buckle.