IWC Schaffhausen is the only major Swiss watch manufacturer located outside the traditional watchmaking cantons of Geneva, the Jura, and the Vallée de Joux, founded instead in 1868 in the Rhine city of Schaffhausen by American engineer Florentine Ariosto Jones, who sought to combine American industrial methods with Swiss horological craftsmanship. This engineering DNA has defined IWC ever since — a watchmaker known for technical solutions, durable tool watches, and a distinctly masculine aesthetic rooted in aviation, maritime, and military heritage. IWC's most iconic collections are the Pilot's Watch family — including the Big Pilot and the Spitfire — the Portofino for dress watch elegance, the Portugieser for large-format precision, the Aquatimer for diving, and the Da Vinci for calendar complications. Key pre-owned IWC references include the Portugieser Chronograph ref. IW371202, the Big Pilot ref. IW500401, the Portofino Hand-Wound with the caliber 98295, and the legendary pocket-watch-derived references of the 1970s and 1980s. The perpetual calendar movements housed in the Portugieser Annual Calendar are among the most respected in Swiss watchmaking. DeMesy & Co. in Dallas has been sourcing and authenticating pre-owned IWC watches since 1987.