Justus, great to have another racing collector in the thread, especially a fan of the 1972 STP set. Thanks for sharing the picture. Those are nice looking cards.
I had seen there were Glotzbach, Brooks, Parsons, Hylton cards at auction/for sale on eBay a few months ago, and I noticed that the PSA population had increased recently. Before that, it was at least a year since the PSA population increased for any of the cards in the set.
With the recent find of Lorenzen cards, it seems the portrait version of his card is now accessible to any collector willing to pay for the card. There was only one Lorenzen with car card in that find. I am surprised the Bobby Allison card does not have more of a reputation as a legendary rarity. PSA's population only shows two graded Allison cards, and I have never seen one for sale or at auction. I went probably two years without ever seeing a Petty '72 STP card on eBay, but there have been four or five of them on eBay over the past year.