18k white gold Wrist Chronometer no. 609431

Case: Ladies Reverso type, Patek ref 106, case s/n: 609431. Dial: silver, Patke Philippe, Geneve Movement: s/n; 860396, baguette caliber 7 ligne, Eighteen 18 jewels, All adj, Geneva seal, Patek Philippe & Co., Geneve, Swiss. Provenance: 1932 - Niton, Geneve (still validating) 1936 - Patek Philippe, Geneve 1999 - Antiquorum Antiquorum Auction Catalogues, Lot 482, Geneva, Hotel Des Bergues, 14th November 1999. Case size: 15x32mm, Patek Philippe & Cie, Genève, Réversible, No. 860396, case No. 609431, circa 1936. Extremely fine and rare, rectangular, 18K white gold lady's wristwatch. To the best of our knowledge, very few Réversible Patek Philippe writswatches were made in the 1930's.Only three examples of the gentleman's model, made in 1933, are known to exist:- No. 822399, case No. 609482, in 18K yellow and white gold,it was given as a gift by Charles and Jean Stern to an employee in commemoration of his 20 years of service, published in Patek Philippe Wristwatches, by Martin Huber & Alan Banbery, 1998 Edition, p. 111.- No. 823422, case No. 609483, in 18K yellow and white gold, retailed by Gübelin, Lucerne, sold by Antiquorum in Geneva, April 23, 1995, lot 619, for SFr. 110,000.- No. 823431, in 18K yellow and white gold, sold by Antiquorum in Geneva, March 24, 1985, lot 134. Only two examples of the lady's model, made in 1936,are known to exist:- No. 826097, published in Patek Philippe Wristwatches, by Martin Huber & Alan Banbery, 1998 Edition, p. 116.- No. 860396, case No. 609431, in 18K white gold, now offered for sale. Poinçons de Genève. The voluntary quality control of watches at the Geneva Observatory, was established by a law dated November 6, 1886. Conditions were laid down for the attribution and stamping of the Poinçons de Genève, punch-marks designed as the coat-of-arms of Geneva. Pocket watches, or wristwatches which carry the Poinçons de Genève, considered as an equivalent to a Bulletin Officiel de Marche, punched on a bridge and on the main plate of the movement, were qualified to be officially termed "chronometers". https://catalog.antiquorum.swiss/en/lots/17319 18k white gold ladies reverso Model/Ref 106, Book Patek Philippe, Geneve by Martin Huber & Alan Banbery (1988), page 32, figure no.23, 860392 (1937) does not name the ebauche deliverer but on pag. 98, ref 114a-c, 826097 (1936), they name LeCoultre, but it is most likely Niton. Notice; by a request for information at Patek Philippe - Reverse-type timepiece, Extracts from the Archives responded at June 18, 2020; Dear Sir, Thank you for your message and query. On a general note, please be informed that Patek Philippe never discloses the quantity of watches produced for a specific model. We however confirm to you that our register books show that both of the watches indicated by you (860 396 and 826 097) are "reverse-type" Ref 106.