It's hard for me to answer that because we don't have swing axle Supers in good ole USA, so I have no hands on experience. However, to the best of my knowledge, it shouldn't be any more difficult than a normal pan swap. Keep in mind that the seat tracks are different. The frame head in '75 is shaped a little different on the top (for the R&P steering) but that's not going to be a problem. There is a extra fuel line (on the FI cars) that you won't need. I'm 99% sure it will work.

American Supers never got discs in the front and some European Supers have swing axle. Strange we got the good rear and you got the good front.