I came across a site about an Intermeccanica Omega (Italian car with 289 Ford engine) and somewhere halfway down it shows a picture of the Kelsey Hayes Mag Star wheels, but the caption says: "Amazingly, this Omega still rolls on its original alloy-steel wheels, made in Italy by Campagnolo--and copied later in the U.S. as "Magnum 500s." Tires are brand new radials of the correct size 195/70-14 all around." http://californiaclassix.com/archive/68_Omega_c460.html
I know that Campagnolo used to make wheels for cars, but had never heard they originally designed the Mag Stars. Of course, there was a lot of copying going on in the 1960's wheel business, so I guess it's not impossible. Any truth to the statement on that website?
Of course, the Magnums only look similar but are not copies of these wheels.