Found these rims in the attic..any way to identify the year??

Thx MD!! Now, I think I've narrowed down the year to 1972. There is a copyright stamp inside one of the spokes on the back that says C-72. Don't know if the style was just copyrighted then, or the rims were made then, but it's a start!!

Here's 3 of them cleaned up, working on the 4th!! Ones kinda peeled, and If I can find one to replace it in the next couple months I'll be good to go, if not it's going on as is for now!! Geof