Swiss 18K yellow gold keyless dress watch with a black dial Circa 1940

Gold open faced lever pocket watch 
–
A very rare and fine Swiss, 18K yellow gold keyless dress watch with a black dial, circa 1940. A polished case, inclined bezel, the back engine-turned with a striped pattern. Black lacquered dial with applied yellow gold faceted baton indexes, outer minute track, subsidiary seconds. Yellow gold dauphine hands. A rhodium-plated movement, Geneva striping decoration, 18 jewels, straight-line lever escapement, cut bimetallic compensation balance, blued steel Breguet balance spring, swan-neck micrometre regulator. Dial, case and movement signed.
–
Diameter: 45 mm
–
Signed: Patek Philippe & Cie.  Genève
–
Patek Philippe & Co. dress watches with black dials are exceptionally rare.
–
The case has some scratches, the dial is slightly oxidized and the movement has slightly worn.