Dave, Exceedingly nice Johnston Cookies Henry Aaron! A real beauty. Honestly, that has to be one of Hank's most attractive cards---what a radiant smile. I'm sincerely happy for you.
The ultra-high grade is pretty impressive; I mean, a POP 27 with 10 higher is decent.
The cards left over from the Johnston Cookie promotion were offered in the catalogs of Wholesale Cards Co., run by Bruce Yeko when I bought cards from him in the 60s - early 70s. The provenance of your card might trace back to Wholesale, which would be cool. Just because Yeko and man who owned the company before him dealt with firms to purchase their left over promotion "free prizes" did not guarantee any or all of those cards would be pristine. So many factors played into preserving or harming their condition over these many years. For what's it's worth, I think you did rather well.
---Brian Powell