Okay, this mystery is starting to gnaw at me again. So to recap:
1. The Elton song is NOT one of his singles--but is a fan favorite--and was recorded pre-2011.
2. One of either the target EJ song OR correct Al song was mentioned in the original thread about this. (Here: http://www.weirdalforum.com/viewtopic.php?f=2&t=11022)
3. "Midnight Star" is not the Al song in question.
4. The Al song has not been previously identified as a style-parody of another artist.
So over in the Music forum under Unreleased Tracks, someone who played with Al on some songs posted that he recalls a recording session where they played EJ's "Your Sister Don't Dance (But She Can Rock N Roll)", which is a song off the Goodbye Yellow Brick Road album. I'm convinced that any EJ homage by Al would be based on a song off GYBR because we know that was an influential album for Al. As for which Al song, something about "Don't Wear Those Shoes" always struck me as Elton John-esque...but not quite. That was also one of the few songs mentioned in the original thread. So here's my new guess based on all of this:
"Don't Wear Those Shoes" = "Your Sister Don't Dance (But She Can Rock N Roll)"
Hopefully Bermuda is still checking in so he can tell me if I'm right or not. (Probably not.) (Right, that is.)