Rare Swiss nickel-silver aviator’s pocket watch Circa 1918

Nickel-silver watch made for the Royal Air Force
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A rare Swiss nickel-silver aviator’s pocket watch, circa 1918. 30-hour, non-luminous, Mark V, delivered to the Royal Air Force. A polished case, snap-on back with over arrow engraving, hinged cuvette. Black dial with bold Arabic numerals, outer minute track, subsidiary seconds and matte steel spade hands. A frosted gilt movement, 15 jewels, straight-line lever escapement, cut bimetallic compensation balance, Breguet balance spring, index regulator. Dial, case and movement signed. This watch is sold with a box and certificate of authenticity.
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Diameter: 52 mm
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Signed: Omega  Swiss
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The back threading is damaged.