Vacheron Constantin Patrimony Perpetual Calendar - Ref. 43031

 Introduced in 1983/1984, the Reference 43031 is a highly celebrated "neo-vintage" masterwork. Along with Patek Phillippe's 3940 and Audemars Piguet’s Quantième Perpetual models, this specific reference is credited with saving traditional, high-end mechanical Swiss watchmaking after the devastating Quartz Crisis. .It features a highly distinctive, slim 36mm case distinguished by a dual-stepped bezel and straight, stepped lugs that wear with incredible sophistication on the wrist.  Hidden beneath its solid gold caseback is the legendary Caliber 1120/2. Based on the ultra-thin Jaeger-LeCoultre ébauche  JLC 920, it is widely considered one of the thinnest and most reliable automatic perpetual calendar movements ever developed.  The beautifully proportioned dial displays full perpetual calendar registers: at 12 o'clock the months and 4 year leap year cycle, date track at 3 o'clock, 9 o'clock the days of the week and at 6 o'clock a high-contrast lapis moonphase indicator sitting beautifully above the "Vacheron Constantin Genève" brand signature.    The Reference 43031 is far more than an elite dress watch; it is a monument to mechanical survival. Crafted during an era when the industry hung in the balance, Vacheron Constantin made a definitive statement by packing a complete perpetual calendar and moon phase into a case of impossible thinness.   This model offers an extraordinary entry point into neo-vintage "Holy Trinity" collecting.