excelsior (Jeanneret Frères) - Calibre JB1 (Patente Brevet +3364) - 1850-1900

Historical and extremely rare pre-Excelsior Park Swiss pocket watch, manufactured by Jeanneret Frères in Saint-Imier (c. 1896-1905). An authentic museum piece originally destined for the UK luxury market (estimate of remaining units) that is in extraordinary condition and IN RUNNING ORDER (the balance swings with total smoothness, with a lively and clean beat).
• Movement: First-generation mechanical Calibre JB1 with the characteristic J bridge. Incorporates the legendary curved rack-and-pinion system patented under Swiss Brevet No. 3364 of March 21, 1891 by Albert Jeanneret & Frères. Includes the original spare-parts compartment. The movement is immaculate and protected by its dust cap (cuvette). Chronograph functions fully operable via the crown’s coaxial button.
• Dial: Pristine white porcelain enamel dial, 100% crack-free. Blued steel hands with a spectacular patina and tone. 12 o’clock subsidiary 30-minute register in excellent condition.
• Case: Made in solid high-purity silver (0.935) by the prestigious case-maker Numa Muller (punch NM). The clean weight of the silver case is 35.53 grams (without crystal or movement). Features official Swiss government hallmarks (Three Bears), the London import mark of George Stockwell (GS), assembly number 6, and matching serial number 203971.
A digitized copy of the original technical drawings from the Brevet +3364 patent registered in 1891 is included with the watch. An exceptional opportunity for high-chronometry primitive collectors and investors. International insured shipping.