18k two tone white and yellow gold Chronometer no. -

Case: 18k white gold bezel and back pendant and band yellow gold (33 mm) Dial: silvered matte dial, baton and roman nummerals, hour and minute hand Movement: sn; 860192, small pocket watch movement, nickel lever movement, 18 jewels, stamped twice with Poincon de Geneve quality seals Provenance: 1938 - Niton, Geneve (still validating, ebauche and/or finished by Niton, Piaget, CH Meylan or ?) 1938 - Patek Philippe, Geneve 1988 - Sotheby's Sotheby's, New York, June 22, 1988, Lot 868, Two Tone Gold Openface Dress Watch, Patek Philippe & co., Geneve, No. 860192