Who knows why he didn't just stop the Aligarors trem block with wood but my guess is he liked to tinker with his gear. I often wonder what the E72 tour would have sounded like if he played the Wolf which I've read was taken on that tour and had a terribly tragic fall which ultimately led to its awesome make over.
I don't think Wolf existed in 1972. My understanding was Jerry didn't receive that guitar until sometime in the summer of 1973, with it being played onstage for the first time that autumn. The "terribly tragic fall" happened during the September 74 European tour. And it wasn't that tragic. There was a crack on the headstock, but I believe I've read where Irwin said it wasn't fatal or anything. But since Jerry wanted it repaired, he went and ahead and did the repair, and decided it gave him an excuse to redo the headstock inlay. And I gather that as a result of that, Irwin had to refinish the guitar, and I guess he couldn't just refinish the headstock, he had to do the whole guitar, which is how the wolf sticker got converted into an inlay.
Most of the mods to the electronics, I think, came later. I know when Jerry first started playing Wolf again during the autumn 77 tour, it still had three single coil pickups, and it stayed that way for the first few months of 78. I don't think he added the humbuckers until spring 78.