French gold and enamel ball form pocket watch Circa 1790

Ball shape pocket watch
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A rare and very fine French 18 carat gold and polychrome enamel key wind concealed ball form watch, circa 1790. Gilt full plate fusée verge movement, pierced and engraved balance bridge, silver regulation.
White enamel dial, black Arabic numerals, black outer minute divisions with Arabic numeral 15-minute markers, winding aperture at 2, gilt hands.
Concealed ball form case with speckled multicoloured polychrome enamel decoration throughout.
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Diameter: 25 mm
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Signed: No name