Reference 1526 was Patek Philippe’s first perpetual calendar wristwatch made in series. Launched in 1941, it remained in production until 1952. The first generation, like the present watch, has a double circle around the aperture for the moon phases, one indicating the constant seconds, the other one the date of the month.The present example must be considered amongst the very best preserved specimen of this legendary model as it appears to be in virtually unworn condition. Its case does not show signs of wear and certainly no signs of polishing. The original leather strap, still after 70 years, appears to be unworn. Much to the collectors delight, the original certificate and invoice have also been preserved until to date. A more complete package and better preserved complicated Patek Philippe wristwatch from the early 1940s is a near impossible find.