Patek Philippe Perpetual Calendar Chronograph 3971

A RARE 18K YELLOW GOLD PERPETUAL CALENDAR CHRONOGRAPH WRISTWATCH WITH SNAP-ON SAPPHIRE CRYSTAL DISPLAY BACK 1986 REF 3971EJ FIRST SERIES MVT 875071 CASE 2824133 18K YELLOW GOLD diameter 36 mm , • cal. 27-70Q nickel lever movement stamped with Geneva seal, 24 jewels, Gyromax balance, adjusted to heat, cold, isochronism and five positions • two-toned silvered dial, subsidiary dials indicating constant seconds combined with 24 hours, 30 minute register combined with leap year indication, and moon-phases combined with date, apertures for day and month, baton indexes, feuille hands • circular case, round chronograph buttons, snap-on sapphire crystal display back • case, dial and movement signed • with an 18k yellow gold Patek Philippe buckle