The outer sheet metal skin is the same.
Internally, the 67-72 doors have an integrated steel upper panel that is painted either the outside color of the car, or a color to match the interior. The 1973-76 doors have a molded plastic upper door panel that is held in with several #10 screws. The inside door handles in the 67-72 models are just forward of the arm rest pad. The 73-76 inner door handles are up higher and are of a different design.