Very rare Swiss gold open faced minute repeater Circa 1940

Yellow gold minute repeating watch by Vacheron Constantin
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A very rare and attractive Swiss 18 carat yellow gold open faced minute repeating watch by Vacheron Constantin, circa 1940.
18K yellow gold, open faced, keyless-winding, round-shaped, thin pocket watch.
Champagne dial with Breguet numerals with subsidiary seconds at 6, minute repeating on two steel gongs, activated by the slide at 8 o’clock.
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Diameter: 48 mm
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Signed: Vacheron Constantin Genève
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The Extract from the Archives, dated September 2019, mentioned that this watch was manufactured in 1940. According to the manufacture’s “Livre d’Etablissement des montres à sonnerie”, the watch was delivered to Beyer, Zürich, on April 16, 1944.