This Type of structure has a protracted history at Patek, relationship again into the early sixties Along with the ref. 2597 Travel Time Calatrava. As James Stacey outlined in his Arms-On Together with the 5164R in 2019, the movement from the 2597 originated through the mind of Louis Cottier – https://www.watchesworld.com/germanys-top-10-favourite-luxury-watches/