Dial, case and movement signed. DIAM. 37 mm. THICKNESS 14 mm. Approx. overall length 160 mm. REF. 2438 Production of reference 2438 began in 1952 and ceased in 1963. Reference 2438 is similar in design to reference 2497, uses the same 27-SC Q caliber movement, but was designed with a water resistant case back. It is the only vintage perpetual calendar watch made by the firm to feature a screw back. Between references 2497 and 2438, a total number of only 179 examples were produced, making both models amongst the rarest perpetual calendar watches made by Patek Philippe. Both models are featured in "Patek Philippe Wristwatches", by Martin Huber and Alan Banbery, 1998, pages 285-287. This particular example unseen to the market, is the first example ever to feature an insignia at twelve o clock. It is part of the second generation of 2438 featuring baton indexes rather than the arabic found on the first generation examples. Interestingly enough its movement number would indicate it was made towards the end of the production, it was actually manufactured in 1955 but only sold in 1963, the last year of the 2438. Originally sold to the US, further confirmed by the high quality 18k Tiffany & Co tile bracelet, the watch has remained in excellent condition, exhibiting beautiful stepped lugs, a deep hallmark, and the original dial that has developed a wonderful patina over time. The unusual insignia at twelve o clock is of unknown origin, the consignor claims that the watch was gifted to a prominent person that was part of the royal dynasty in the former Kingdom of Mysore before joining India in 1950, although this information cannot be verified.