Oh yeah I saw that for sale, nice looking example! Unfortunately I'm not in the market to buy another 75, unless it was dirt cheap!
I was sold a set of 15 inch revolutions, but after spending a load of money on a re-furb it turns out they are 14 inch revolutions, so look a bit small. Gutted, never take someone's word, even if they are heavily into Alfa 75's!
I have a set of four, definitely 15", x 7J, I believe. They came off my '88 3.0 after it got totalled in France in the mid '90s. They have a set of Yokohama A510s in 195/50, which looked fine last time I checked. You might want to have the wheels refurbished at some point, and the steel inserts the wheel nuts bear upon need de-rusting or replacing.
I hung on to them as I have trouble letting go of this stuff, I was sure I'd have another 75, and I did but didn't need them then either. See my first post in intros.
I'll take some pictures when I am around Friday afternoon.