Patek Philippe Perpetual Calendar Chronograph 3971

A FINE AND VERY RARE YELLOW GOLD PERPETUAL CALENDAR CHRONOGRAPH WRISTWATCH WITH GILT DIAL, REGISTER, MOON-PHASES AND SNAP-ON SAPPHIRE CRYSTAL DISPLAY BACK 1987 REF 3971J FIRST SERIES MVT 875074 CASE 2824136 diameter 36 mm , • cal. 27-70 manual winding damascened nickel lever movement stamped with the Geneva seal, 24 jewels, free-sprung Gyromax balance, adjusted to heat, cold, isochronism and 8 positions • champagne dial, applied square and baton numerals, subsidiary dials for constant seconds combined with 24-hour indication, 30-minute register combined with leap year indication and date combined with moon-phases, twin apertures for day and month, calendar in German • 18k yellow gold case, stepped down-turned lugs, snap-on sapphire crystal display back • case, dial and movement signed • 18k yellow gold PP buckle , Extract from the Archives