This Kind of layout has an extended background at Patek, dating again on the early 1960s Using the ref. 2597 Travel Time Calatrava. As James Stacey pointed out in his Hands-On Together with the 5164R in 2019, the movement during the 2597 originated with the thoughts of Louis Cottier – https://www.watchesworld.com/germanys-top-10-favourite-luxury-watches/