Swedish extremely rare watch with Sully escapement Circa 1790

Gold open faced pocket watch by Jacob Kock
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An extremely rare Swedish pocket watch with Sully escapement, circa 1790.
18 carat rose gold case with case maker punch mark “OEM”. Signed enamel dial with Arabic numerals and gold Louis XVI hands. Full plate movement, keywind, firegilt, signed, chain/fusee, solid movement pillars, three-arm brass balance, blued balance spring, fine florally engraved and pierced balance bridge.
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Diameter: 53 mm
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Weight: 98 g
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Signed: Jac:Kock Stockholm
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Jacob Kock was born in 1737. He was clockmaker to King Gustav III. Many of his watches are in several museums today. He died in 1805.