German lever one minute tourbillon watch Circa 1981-1983

Lever watch with Guillaume balance, thermometer and power reserve 
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A very fine and rare German 18 carat gold open faced keyless lever one minute tourbillon watch with Guillaume balance, thermometer, power reserve, bow winding and hour setting mechanism, circa 1981-1983. 1/2 Nickel finished fully jewelled lever movement, Guillaume balance, non magnetic Nivarox Prima balance spring, three armed one minute tourbillon carriage by Richard Daners, glazed dust cover. Engine turned silver dial with Roman numerals on blank chapter ring, blued steel Breguet hands, two fan shaped sectors for thermometer graduated from 5 to 30 degrees Celsius, 48 hours power reserve indication and subsidiary seconds. Engine turned case, screwed back, winding and setting mechanism operated by twisting the bow. Case stamped TE, dial and movement signed and numbered. Comes with original certificate and presentation box.
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Diameter: 56 mm
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Signed: Thomas Engel