I find the seats reminiscent of the Ferrari's and Citroen CX chairs from back when. Really cool, but in a W116? A little strange, especially if you're a long-time connoisseur.
But, on a different note.. Next-in-line supercar to mention back when, was the Citroen XM/Maserati. Had such seat-styles as well. In a parallel universe, it could have been the standard for 6.9 as well. Those are sturdy leather Italian muscle car seats, not the overly comfy, wobbly German middle-aged-man-with-wide-load cushions that all the Mercs had those days.