Fine Swiss 18k gold pocket watch playing music Circa 1820

Gold open faced cylinder music watch
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A fine and rare Swiss, 18K gold pocket watch playing music, circa 1820. An Empire, engine-turned case with blue enamel border, polished band, bolt at 1 for locking the music. Hinged gilt brass cuvette. Gold, engine-turned dial, with black Arabic numerals on circular white enamel reserves intersected by engraved stylized leaves, white enamel outer minute track. Blued steel Breguet hands. A gilt movement, fixed going barrels for the going and musical trains, cylinder escapement, brass three-arm balance, blued steel flat balance spring, polished steel endplate, and an index regulator. Numbered on case and cuvette.
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Diameter: 40 mm
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Signed: Anonymous  Swiss
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The case has some dents.