I have finally located the ride height specs in the "M-B Technical Data 1980" and I include a copy of what it says but I am not sure how you apply it.
I measured my car today (Euro with 16 inch wheels) with a straight edge at the highest point of each wheelarch opening and the fronts were both 66.5 cm and the left rear was 63.5 cm and the right rear 63cm - with the motor idling.
Reading the specs suggests that the front ride height is the same as a Euro but the rear is 6mm higher. It must be the bumpers that change the ride height visually.
Bill
1979 Euro 6.9 with AMG modifications #5554
1979 450SEL plus another 1979 for spares