72. 72Y Vacheron Constantin. An 18K gold automatic calendar chronograph wristwatch with sigma dial Vacheron Constantin. Chronographe bracelet en or jaune 18K (750) avec cadran sigma mouvement automatique Model: Patrimony Chronograph Reference: 47001 Date: Circa 1990 Movement: 51-jewel Cal.1126 automatic, adjusted to heat, cold, isochronism and 5 position, 21K gold rotor edge, No.748277 Dial: White tapisserie grid, applied 18K gold baton hour markers, black outer 1/5th second divisions, sunken subsidiary dials at 6, 9 and 12 for seconds, 30 minute and 12 hour recording, 18K gold pointed baton hands, blued steel centre chronograph hand Case: Brushed and polished round, back secured by 4 screws, stepped bezel, crown flanked by twin pushers, No.591822 Strap/Bracelet: Brown alligator leather Buckle/Clasp: 18k gold buckle Signed: Case, dial & movement Size: 38mm Weight: 73,40g