over the style of the back of the seatback. I seem to remember that my Duetto (back in '75) had the type of seat shown in the pic. Notice the back of the seatback being 2 pieces. A few guys are telling me that the orig, seats had a seatback with a smooth 1 piece seat back or a smooth 1 piece seatback with fake stitching.
My seat covers from World Upholstery looked like that with the upper part of the back too long. It looks like it should be wrapped around the cross bar that runs horizontal across the upper back, but it really should be wrapped around the upper rounded part of the seat back structure. It will basically wrap around about 1" of the back perimeter. Does that make sense? Then the seat back cover will slip underneath the perimeter.