Nice writeup. I discovered this process when I got my hands on some cheap electric memory seats. They were the right colour, but the leather on them was rubbish, so I transplanted the leather and foam from my old manual seats.
I've used the technique to swap out the seat back frame from an electric seat which had suffered too long with the twisting caused by the motor drive cable fault. The welds in the seat frame crack at the top corner.
If you happen to find one really good leather skin from an E32 or E34 front seat in Natur colour please let me know. I've been looking for years up here and never got one.
Some things that I've found
- Electric and manual seat skins can be interchanged
- Left and right seat skin can be swapped around. You will need to cut holes in the leather for the levers/switches on the opposite side, but the excess holes are all hidden under the trims on either side of the seat base.
- E34 and E32 seats and skins are completely interchangeable