French rare Louis XVI style pocket chronometer Circa 1870

Gold pocket chronometer by Maingourd Frères
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A very fine and rare French 18K gold open faced pocket chronometer, circa 1870. Accompanied by the original presentation box. Plain case in Louis XVI style, monogrammed AG on the back, curved lateral hinge. Very rare ¾ plate chronometer movement, chain and fusee, extravagant fine adjusting device, helical hairspring, screwed gold chatons, balanced lever, very rare Malteser mechanism disengaging and protecting the chain from getting more wound up by the crown. White enamel XVI dial with black Roman hours, red Arabic five-minute numerals and pink gold hands.
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Diameter: 47 mm
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Weight: 90 g
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Signed: Maingourd Frères Rue Dumas 23 Le Mans