Noticed that there's a writeup on the find in the April 2023 PSA Magazine.
Pages 25-26, here:
https://issuu.com/psamagazine.com/do...gazine_rgb_300
The article suggests that there are 3 copies of each card in existence, for 54 cards total, with one of the sets being in uncut sheet form. Although I wouldn't be surprised if the original uncut sheet has been cut up by now.
To my knowledge, there are 3 of the Mays in PSA holders, and at least one in a SGC holder. Unless someone crossed one of them over, that would make at least 4.