WIW - 15x8 6 lug steelies

[tjsblazer]

Guys, I know these rims usually sell on the board in the $80 - $100 range per wheel but these are slightly different than others I've owned or saw. I just picked up this pair at the Wreckers and they had them marked as off a '79. They have surface rust only but the difference is the 3 small holes in between the lug holes. I know you would never see these once capped or maybe not even care but I was curious. All other dimensions and appearance is the same as others I've had. Were these factory to hold a smaller cap or did a P.O drill them?