Swiss 18K gold pocket lever Royal chronometer Circa 1915

Gold open faced lever pocket watch
–
A very fine and rare Swiss, large, keyless, 18K yellow gold pocket lever chronometer royal, circa 1915. A polished case with a sunray engine-turned case back. Hinged gold cuvette. White enamel dial with bold upright Arabic numerals, outer minute track, large subsidiary seconds. Gold spade hands. A frosted gilt movement, 18 jewels, wolf’s tooth winding, straight-line lever escapement, cut bimetallic compensation balance, blued steel Breguet balance spring, and swan-neck micrometre regulator. Dial, case, cuvette and movement signed.
–
Diameter: 57 mm
–
Signed: Vacheron & Constantin  Genève
–
The case is slightly scratched.