Josh Gibson - Type IV Photo question

[Snapolit1]

I recently purchased the below Type 4 Josh Gibson photo from Heritage. Love the image and it's pretty well known.

Here's my question. Hopefully I don't expose my ignorance too badly. . . .

The photo is marked Type 4 and PSA titles it "Josh Gibson in 1945." The slug on the side is dated 2/8/72 and references Gibson and Buck Leonard being voted into the Hall of Fame. The slug goes on to say "Gibson, in 1945 file photo . . . ." Heritage describes it as "a wire photograph of the HOFer from the 1940s produced in 1972."

I guess my question is what does 1971 necessarily have to do with the photo. I realize in 1971 someone at UPI created this image w/ the slug to the side. But they reference the photo as being a 1945 file (not a wire) photo. I'm assuming the photo wasn't printed again in 1972, but maybe that's 100% the wrong assumption. Does the Type IV designation apply to the actual photo? Looks to me like a photo was taken from a file, glued onto a new backing, and a slug was affixed. I can see through the photo on close inspection that there is writing on the back of the photo. (Why would someone write on a photo if they just printed it to to glue on a new backing?)

Ok, that's more than one question. Appreciate any insights/thoughts.