The Allmen Bros. cover was used after one of the band members was killed in an accident with a peach truck. Kind of a bit of dark humor. What made me wonder about Mick's cover being an ode to the Allmen Bros one is whether there is some allusion behind the avocado along the lines of the one the peach truck cover suggests. As for the surreal cover, I have never seen that. Perhaps there is some link--especially if Lindsey does show up somewhere on Mick's cd. I could come up with a theory about Lindsey's surrender of his material to FM for SYW being a figurative death of the solo artist and the use of the similar image as a statement to that. My theory would be supported by the fact that "Eat a Peach" was an effort to salvage work the band had done on on a new album prior to the musician's death (his name was Duane Allman, by the way) by recording a bunch of additional stuff, eventually winding up with a double album. But since SYW didn't end up as a double album, my theory would be faulty, wouldn't it....
I see the Allman Bros. cover like this: The peach represents the work that Duane Allman participated in, while the truck symbolizes the band's effort to move on, while including--or carrying or containing--Duane's work. All this makes me wonder if the cover has been around for awhile because if it has it seems like it would be better suited as the cover for SYW, with the avocado--a fruit generally associated with California--being a symbol of Lindsey (a Californian) and the truck representing FM and its "carrying" Lindsey's work into a "sellable" product--a FM album.
John