Does your trusted Porsche wrench work on a lot of early 928's? If not he might as well be your trusted Buick wrench.
My 83 is a European delivery car, but other than a service stamp from Stuttgart for the first service at the factory its a 100% US model, nothing Euro about it.
A friendly suggestion, put your initial efforts into making your car safe and properly running, then enjoy it a bit as Porsche intended before changing anything.
Early seat rails are slightly different, bolts are one size smaller, and I think the mounting area is shorter, but nothing seriously preventing your adding 45 lbs of motors etc. to the lowest powered model of 928.
