English gilt duplex made for the Chinese market Circa 1820

Gilt, enamel and pearl set centre seconds duplex by Richardson
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A fine English gilt, enamel and pearl set open faced key-wound duplex watch with centre seconds made for the Chinese market, circa 1820.
Partially chased and engraved gilt finished duplex movement. Gilt cuvette. Off-white enamel dial with Roman numerals, outer minute track and centre seconds. Large case, polychrome enamel portrait of a lady set within a polychrome enamel floral and wood frame to the back, all within a blue enamel guilloché background, split pearl set bezels, pendant and bow, coin edge band, hinged case. Movement signed and numbered, case and cuvette numbered.
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Diameter: 58 mm
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Signed: Richardson London