Swiss brass small two day chronometer watch Circa 1915

One of presumably only three pieces
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An extremely rare and small two day chronometer pocket watch with an Extract from the Archives made by Vacheron Constantin SA in Geneva, Switzerland, circa 1915. The numbered case of this watch was crafted from brass and is fitted with original gimbal suspension in the original three part mahogany box. The silvered dial features Roman hour numerals, an outer minute track, a subsidiary seconds dial at 6 o’clock, 52 hour power reserve indicator at 12 and blued steel spade hands. The numbered movement is fitted with a spring detent chronometer escapement and a helical hairspring.
The dial and movement are signed.
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Diameter: 65 mm
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Dimensions:  135 x 135 x 135 mm
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Signed: Vacheron & Constantin Genève
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The copy of the Extract from the Archives is included and confirms both numbers 229564, 370698 and the originality. This timepiece was sold in 1915.
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Antiquorum in Geneva sold one more of these extremely small chronometers, number 388127, for CHF 87.400. According to research by Antiquorum in 1992, Vacheron & Constantin confirmed that only three of these chronometers were made. At the time, it was assumed that the other two chronometers were lost.