This Type of layout has a long history at Patek, courting again into the early nineteen sixties Together with the ref. 2597 Travel Time Calatrava. As James Stacey stated in his Hands-On Using the 5164R in 2019, the movement inside the 2597 originated within the brain of Louis Cottier – https://www.watchesworld.com/germanys-top-10-favourite-luxury-watches/