Rare Swiss gold hunting cased complicated watch Circa 1917

Gold lever with chronometric balance, moon phases and perpetual calendar
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A very fine and rare Swiss 18 carat gold hunting cased keyless lever watch with chronometric balance, moon phases and perpetual calendar, circa 1917. Mechanical movement (circa 1891), 20 jewels, bimetallic chronometric compensation balance with gold poising screws, micrometer regulator, wolf’s tooth winding. Gold cuvette. White enamel dial with black Breguet numerals, blued steel spade hands, outer railway minute divisions, four subsidiary dials for moon phases and lunar calendar, day, month, constant seconds and red date. Plain case. Case, cuvette, dial and movement signed and numbered. Comes with original certificate and box.
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Diameter: 54 mm
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Signed: Patek, Philippe & Cie Genève