Reference 3940 is one of the most iconic models that Patek Philippe ever produced. Launched in 1985 under the tutelage of Mr. Philippe Stern, it marked a design shift for the manufacture's perpetual calendar models. No longer sharp and elongated, the case transformed into a tonneau-shaped Calatrava-style design. Most notably, the first 25 examples were specially made for the 225th anniversary of Chronométrie Beyer and displayed a champagne dial with the individual number at 6 o'clock.

This beautiful first generation reference 3940 is very remarkable due to a number of reasons. It most notably displays a champagne dial, which is confirmed by the Extract from the Archives. Shimmering and finished with utmost care, this champagne dial is visually arresting. Mr. Stern himself donned a reference 3940 with champagne dial, attesting to the beauty of this exact model. The present watch is one of only five known first series examples to be fitted with the present dial.

Interestingly, the Extract from the Archives mentions that the original solid caseback was replaced by a sapphire-crystal case back during a servicing in the Patek Philippe workshops in 1998. First generation reference 3940s were fitted with a solid caseback. It thus comes as no surprise that a loyal and privileged client of Patek Philippe would want an upgraded caseback to admire the beautifully-finished caliber 240Q. Such requests were only granted on a case by case basis, and it is not improbable that this wish was approved by Mr. Philippe Stern himself. This feature adds another level of desirability and exclusivity to the present timepiece.