A rather daft discussion has been going on on PP regarding the composition of Fuchs rims. Here is the response that I got from the manufacturers, Otto Fuchs.

Q: Can you tell me what aluminium alloy was used in the Fuchs Porsche rims of the 60s and 70s?

A: We used 6082(USA), 3.2315(DIN), AlMgSi1(Type) or FUCHS Designation AS10.62,
.62 indicates Temper Disignation.
Best regards Joachim Boehme