You do realise that it probably wont hurt to try replacing the partitions and shove it on a USB loader. The controls are probably hardcoded into the game partition and therefore if you put a GC game in it it will automatically use the GC controls.
Admittedly, I dont know much about how the wii works, but I think the games are just ports and not re-makes therefore it can't hurt to try. At most you will waste an hour or so of your time. If someone tried this and it did work, I'm sure it would be all over the forums, so it doesn't look like someone has tried (and succedded).
Just jump in there, and tell us what happens. I would, but I don't have access to a backup of MP3.