So here’s the short version of the backstory. If you flip through the 1992 tome L’Univers Vacheron Constantin Genève by Carole Lambelet and Lorette Coen, you’ll eventually stumble upon a lone photo of a tonneau-shaped minute repeater with retrograde calendar marked “ref. 3620.” It’s arranged in a grid with countless other pocket watches and wristwatches of all kinds, and you’d be forgiven for turning the page and not even noticing it. But for die-hard collectors, this unusual piece, dating to the 1930s, became a white whale. Repeating wristwatches from that era are already rare, but the combination of the tonneau case, crown at 12 o’clock, Brooking Madrid signature, retrograde calendar and day-of-the-week indicator, and repeater slide on the right side of the case, not to mention the fact that it came from Vacheron Constantin, made it almost impossible to believe. And for the last 27 years, this lone photo was basically all anyone knew about this watch. Many assumed it was lost.