Interestingly the seller describes them as a set of 6" fronts and 8" rears, both of which are wrong.
The difference in the castings (rim details, spoke thicknesses etc.) suggest this was a "set" scrounged up from various cars and probably not produced all at the same time. Given the weird bubbling, I wonder if these may be a mix of magnesium and aluminum as well. Hard to tell without weighing them. The center discs are later repros not originals. But, if you need a set... where will you find another "this cheap"?

Mark