I'm curious...
What's the difference between the alloy stock rims (Alpina style) regarding E3 vs. E9?
E9 partnr. 36 11 1 113 085
E3, E12... partnr. 36 11 1 119 534
It could be that the later e3s built concurrently with e12 may have had the turbine style wheel, but just a guess. The e12 came out in 1972 in Europe.