Swiss 18 carat white gold open faced lever watch Circa 1950

A Swiss 18 carat white gold keyless wind open face pocket watch, circa 1950. 18 Jewel Cal.17-170 Swiss lever movement, adjusted to heat, cold, isochronism and 5 positions, Seal of Geneva.  Brushed silvered dial, black Arabic numerals, outer silvered dot minute divisions, subsidiary seconds at 6 and black pointed baton hands. Polished hinged case. Case, dial and movement. With Albert chain and Patek Philippe box.
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Diameter: 44 mm
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Signed: Patek Philippe Genève