IWC Schaffhausen
The International Watch Company, founded by the American Florentine Ariosto Jones in Schaffhausen. Known for pilot’s watches, the Portugieser and the Ingenieur.
The American Florentine Ariosto Jones wanted to combine American industrial production with the skills of Swiss watchmakers and chose Schaffhausen, where the Rhine could drive the machines. The firm is therefore called the only major watch factory in north-eastern Switzerland.
The Portugieser of 1939 was made, according to tradition, for Portuguese merchants who wanted an accurate watch as large as a pocket watch. The Mark XI pilot's watch of 1948 and the Ingenieur of 1955, which protected the movement from magnetic fields, are other classics. IWC is now part of Richemont.
The movement number can be verified in the firm’s archives; the Probus Scafusia mark on later watches.