Confirming
@r44raven's post. Seats are 100% leather on all surfaces (including the headrest), and the door cards are vinyl/MB Tex. The removable front seat-back panels (which the leather seat-back pockets attach to) I believe are not covered in leather. For later cars, the center front seat armrest/telephone compartment should also be covered in pebbled grain leather, I believe.
I am not sure what the center armrest on the earlier cars (which is a wide cushioned pillow that folds up and down) is covered with, but I believe it is also leather.