Please accept my condolences. Love that car and it appears to be original down to the magnum 500 wheels. If you ever want to find out, then the originals have numbers stamped on them. I've got a set of original 14" and 3 x 15" and both sets have this pronounced concave on the outer lip. My repops don't but after looking at repops online, they appear to have them aswell. Most if not all vendors are selling them with 4.25" backspacing for our cars and claim that's what they came, but both my original 14's and 15's have 4" backspacing.
Thanks it is raining with some snow now sooooo I will pull a wheel and look for a parts number.....I appreciate the help......so much to learn.