Patek Philippe Perpetual Calendar Chronograph 3971

A FINE AND RARE YELLOW GOLD PERPETUAL CALENDAR CHRONOGRAPH WRISTWATCH WITH REGISTER AND MOON-PHASES 1990 REF 3971EJ MVT 875586 CASE 2856574 diameter 36 mm , • cal 27-70Q manual winding nickel lever movement stamped with the seal of Geneva, 24 jewels, free-sprung Gyromax balance, adjusted to heat, cold, isochronism and eight positions • silvered dial, applied gold bullet and square indexes, apertures for day and month, three subsidiary dials, the first and the third engine-turned, indicating constant seconds combined with 24-hour indication, 30-minute register combined with leap year indicator and date combined with fan-form aperture for moon-phases • 18k yellow gold circular case, concave bezel, screw-down sapphire crystal display back • case, dial and movement signed • with an 18k yellow gold Patek Philippe deployant buckle