I was at the 1975 Indy 500 when the rainstorm hit and Bobby Unser kept control in that downpour to win it. I remember those Buick pace cars too, thanks very much for these pictures!
Believe it or not, I received all these miniatures for free, made by an English enthusiast. We met on a Facebook page, and I invited him to join the group called "American model cars in 1/43," of which I'm one of the administrators. When this member posted pictures of these seven homemade pace cars, I asked him how he made them. He kindly shared his expertise with me, and then offered to send me the one I wanted to reproduce first: the 1913 Stoddard Dayton. When I asked him the price, he said it would be a gift between collectors. And when I received his package, all seven pace cars were inside :