Fine Swiss gold open faced lever pocket watch Circa 1916

A fine Swiss gold open faced keyless lever watch, circa 1916. Cal. 19”’ manual winding jeweled gilt lever movement with moustache escapement, cut bimetallic balance, index regulator, hinged gold cuvette. White enamel dial, Breguet numerals and subsidiary seconds. 18 Carat gold case, hinged case back. Case, cuvette and movement signed and numbered, dial signed. With a Patek Philippe Extract from the Archives confirming the production in 1916 and sale 1n August 1919 and a presentation case.
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