Hello , I had a chance to see an all original STANDARD 1930 roadster and it had embossed cardboard on door and kick panels, rest was a artificial leather that was basically painted cloth with a grain pressed into it. Similar to old type “oil cloth “..As mentioned this was a standard model, black interior , all artificial leather. It common even today for leather interior is only the seating surfaces,unless it’s an early 911 Porsche , Germans overbuild everything!