Beginning in 1939, Rolex launched reference 3525, which was one of the brand’s first chronograph wristwatches fitted in an Oyster case. It remained in production until 1945, and was produced in a variety of metals. This watch is an early example of the reference manufactured in 1942. Unlike later models that had the serial numbers engraved in between the lugs, this watch displays them on the outer caseback. Reference 3525 has delightfully been nicknamed the “Monoblocco” by Italian collectors, in reference to the fact that the entire case including the lugs and bezel were manufactured in “one block” with the exception of the screw-down caseback. The completely unrestored black, multi-scale dial has aged to a wonderful shade of dark brown. The present example features gilt text with both a tachymeter and telemeter scale and “Fab Suisse” written on the lower edge of the dial by 6 o’clock. The luminous material on the hour markers and hands are original and intact - uncommon for a watch of its age. The satin-finished stainless steel Rolex bracelet is remarkable, and preserved in overall excellent condition. For true vintage watch lovers, this beautifully aged watch comes accompanied by its original presentation box with the retailer signature in Enrico Nattich, Fiume, and is a rare opportunity for savvy collectors.