Patek Philippe. A fine 18K gold openface perpetual calendar keyless lever watch with phases of the moonSigned Patek Philippe, Genève, retailed by Hausmann & Co., movement no. 931'261, case no. 327'507, ref. 725/4, manufactured in 1956Cal. 17-170, with nickel-finished lever movement stamped twice with the Geneva seal, 18 jewels, monometallic balance, micrometer regulator, the gilt matt dial with applied baton and Arabic numerals, gold dauphine hands, aperture for the combined month, date and day indication, subsidiary dial for phases of the moon combined with constant seconds, in plain circular case with snap on back, case, dial and movement signed46 mm. diam.