Unusual French open faced Oignon pocket watch Circa 1740

Silver Oignon verge watch
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An unusual French oignon with alarm,  Fresne a Annecy, circa 1740. A very solid silver case, peripheral sound openings, bell, signed verge movement with square pillars, two barrels for movement and striking train, splendidly decorated enamel dial, unusual constructed central alarm disc above the square, convex hour, gilt decorative hands.
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Diameter: 55 mm
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Weight: 175 g
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Signed:  Fresne  Annecy
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Fine hairlines and minimal professional restoration on the dial, movement intact, striking mechanism needs adjusting.