This platinum simple calendar wristwatch, with moon phases at 12 o'clock, is an interesting and rare timepiece, even though its case has been custom made by the current owner. hn order to evaluate this timepiece appropriately, we have chosen to relate the facts and documents that have resulted from the research made. Specifications of the watch - 11 "' movement, N° 20514, made by LeCoultre and sold to Patek Philippe in 1903 - original Patek Philippe dial - original platinum crown - platinum case made by Jean Pierre Hagmann in 1991 Tracing the history of the watch - This watch has a sound provenance since it comes from the Borghese family, an eminent Roman family, by whom this watch is still remembered as the platinum watch bought in the 1930 's. - During WW II, at the time when, in Italy, gold and all precious metals had to be donated to the nation, the movement, together with the dial and platinum crown, were removed from the platinum case which was given to the State. - Some 10 to 15 years ago, the then-owner gave the movement, N° 20514, to a friend with a passion for watches, who is the current owner and who having kept the movement a while, decided to have a case custom made for it. - On 20 April 1991, the platinum 950 case, exactly like the original, was made by Jean Pierre Hagmann, specialized case-maker in Geneva, and delivered to the current owner on 10 May 1991. - The watch so completed was taken to Patek Philippe in Geneva for a certificate, and, not finding any trace of it in their archives, they were unable to deliver such a certificate. Patek Philippe did not certify the timepiece then and never will. - In the meantime, the current owner made further research on this watch, and went to Jaeger-LeCoultre who confirmed in their certificate dated 16 December 1986 that the movement, N° 20514, was indeed a LeCoultre calibre 11 HPS and that it was recorded in their books as sold to Patek Philippe in 1903. Further information - UTO, Ziirich, sold a watch similar to the present lot, on 22 November 1982; and, similarly, this watch was signed Patek Philippe on the dial, with no signature nor numbers on the platinum case or the movement. - Henri-Daniel Piguet, son of Victorin Piguet, recognized the calendar level on this movement as a prototype made by the workshop of Victorin Piguet, an Sentier, for Patek Philippe. Conclusion In our opinion, according to the analysis of all the documents and the information at hand, having listened to those who have been involved with this watch and considering that the Zurich auction house UTO sold a similar wristwatch with the same peculiarities, seemingly another prototype, we feel that Henri-Daniel Piguet ' s recollection on this matter is the solution to the dilemma. Therefore, in our view, it is more than likely that these prototypes were made and sold in the 1930 ' s, without returning to the Patek Philippe manufacture. The watch is accompanied by the following documents: - Jaeger-LeCoultre, Certificate of Authenticity, dated 16 December 1986, Le Sentier. - Jean Pierre Hagmann, Certificate, dated 10 May 1991, stating the (new) platinum case was made on 20 April 1991. Simple calendar wristwatches with moon phases at 12 o 'clock Made between the 1920's and the 1930's, by Patek Philippe, they had either a cushion-shaped case, of which 3 examples are known to exist today, or a round case ( Calatrava, Ref. 96) of which 7 examples are known to date, not including the present watch. They were usually made in yellow gold or platinum. During the I930's, a few perpetual calendar Patek Philippe wristwatches were produced and, in 1941, Patek Philippe launched two series: - Ref. 1518 (perpetual calendar chronograph wristwatch, made in 281 examples); and - Ref. 1526 (perpetual calendar wristwatch, made in 210 examples).