Wow...late 1960s American Torq Thrust Magnesium, 15x7, 5 on 4.75"
 

These are nearly impossible to find in 15x7, in GM bolt pattern. Nice wheels and probably not too far out of line on price. I'm impressed that the seller even had them Zyglo'd so you know they're structurally sound.

Link to Original Torq Thrust Magnesium Wheels auction

https://i.ebayimg.com/images/g/hsMAA...AA/s-l1600.jpg

I literally just found a set of these but without the D spokes.