English gold precision pocket watch with tourbillon Circa 1913

Gold open faced pocket watch
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An important precision pocket watch with tourbillon, tested at the Kew Teddington Observatory in 1918. 18k gold case, circa 1913, polished, tiered, glazed movement, case marker’s punck mark “FT” Dial is enamel, radial Roman numerals, auxiliary seconds, 30h power reserve indicator, blued spade hands. ¾ plate movement, frosted, gilt, chatoned, signed, finely polished steel tourbillon cage, optionally keywind or crownwind, chain/fusee,  gold screw compensation balance.
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Diameter: 54 mm
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Weight: 144 g
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Signed: S.Smith & Son ltd London