Legit, who knows?! But Masto offered this 1967 Topps Baseball 3rd-Series 24-Count Wax Box for sale in August 2003 with a minimum bid of $1500.
Hank Aaron and Ernie Banks are in the third series, but interestingly, PSA hasn’t designated any of their 77 graded wax pack examples as being from the third series; 22 are undesignated, and then are the 1st, 4th, 5th, 6th, and 7th series packs. FWIW, all the graded 4th-series packs I ran across offered the “All Star Pin-Up Inside.” REA sold this one for $3960 in their Spring 2024 auction.
I asked some folks on the Facebook Vintage Wax and Packs group how Mastro could say the packs were the third series. They surmised Mastro pressed some packs to see the cards and determine the series. I had been wondering if the insert or wrapper color 1967 prevented that technique. I think Topps only used that specific wax box design (advertising the pin-ups) after the first few series were released; if you have more info about this, please leave a comment. Here’s an example from Heritage Auctions of a box without the pin-up ad.
Masto described the box as being in Ex-Mt condition, with a few of the packs showing minor faults or tears but the majority in near-mint condition.