Model: CalatravaReference: 3520Date: Circa 1975Movement: 18-jewel Cal.177 manual wind, adjusted to heat, cold, isochronism & 5 positions, Gyromax balance, Stamp with the Seal of Geneva, No.1369354Dial: Pale champagne, signed Beyer, applied gilt bullet hour markers, outer gilt minute divisions, gilt lance handsCase: Brushed and polished round, screw down back with personal engraving, hobnail engraved bezel, No.2818662Strap/Bracelet: Black Patek Philippe alligator leatherBuckle/Clasp: Signed 18K gold buckleSigned: Case, dial & movementSize: 32mm