My money's on "Song and Dance".
http://www.youtube.com/watch?v=GZDd6xy6e2k
It's one of the few tracks that can't be directly inferred to be stylistically similar to anything else in the score. Ever since I read that interview, I knew that had to be the track.
Sometime soon I'll be posting a write-up on my theories about composer duties. It helped a lot to narrow the possible choices to only three composers, but at the same time, I was already pretty sure Shimomura had only a small part in the score even before I read the interview. Of the three remaining composers, only Mari Yamaguchi has other (known) solo scores/credited music from the SNES Capcom era from which to ascertain her style. For Yasuaki Fujita I can really only rely on Mega Man 3; and Minae Fujii, literally nothing because I don't know for sure if he was in charge of most of MM4.
I've said it before, and I might as well say it again... Capcom really sucks about this kind of thing. Although, I suppose it doesn't help when some composers can't even remember what they did for certain games. I mean, really--how could Shimomura forget what she composed for a game she had to beg to write for? It was only one track.