Travel clock - Jaeger-LeCoultre - Art Deco - Gilt brass - 1930-1940

For sale: a rare JAEGER (Jaeger-LeCoultre) travel clock, reference 521, which belonged to my grandfather and dates from the first half of the 20th century (Art Deco period).
The clock features the celebrated hinged, wallet-style case, made entirely of gilt brass, with the geometric lines typical of the era. The original dial is beautifully preserved, champagne-toned gilt with a two-tone finish; the Art Deco geometric markers and numerals are perfectly legible, and the Jaeger logo is crisp. The model number 521 is clearly engraved in the lower-right corner of the bottom panel.
The smooth outer case back is in keeping with the correct historical configuration for this 1930s clock; the serial number is on the movement inside.
Mechanical condition: in perfect working order. The movement runs regularly and keeps time. 48-hour power reserve. The alarm function also goes off at the set time with a clear sound.
Cosmetic condition: excellent vintage condition. The metal has an attractive patina from age and slight signs of surface oxidation, attesting to its authenticity and period (it has not been artificially polished, in order to preserve its value).
Glass intact.