Rare English silver pair cased verge pocket watch Circa 1749

Silver open faced pocket watch by Robert Sanderson
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A rare English silver pair cased verge pocket watch, circa 1749.
Full plate movement, keywind, signed and fire gilt, with applied engraved ornaments, chain/fusee, square baluster pillars, three-arm steel balance and a very finely engraved pierced balance cock with a grotesque face. Silver and Champlevé dial with inlaid radial Roman hours and blued steel Poker & Beetle hands. Two cases: outer case – silver polished with a large lateral hinge;  inner case – silver polished with hallmarked 1749. Signed on movement: Rob. Sanderson / London / 204, and on dial: Sanderson / London.
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Diameter: 57 mm
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Signed: Sanderson London
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Robert Sanderson London a. 1695, Clockmakers Company 1704- 1731