Well looks like the cover was indeed issued April 7, 1977:
https://www.washingtonpost.com/archi...-a9976bd9ec78/
So that would make the Ghezzi signing an impossibility. It's also in a weird spot, my gut says the rest of the sigs are good, the Ghezzi forgery was added later to add some rarity? The pen looks a little different too. I dunno how crazy golf autograph collectors are and if that really adds any value.
The authenticity question should really be posed to Steve Grad at PSA.