So, er, I was messing around with the titlescreen, and I decided to look through the layer 3 graphics. I looked at 192, 195, 198 and 1AD, which most people would've seen - they are oddly drawn tiles that don't really fit in with anything. I decided to put them in, and ordered them, until they looked like this:
What do those look like? I'll give you a clue: cap.
The upper 3 tiles resemble Luigi's (somewhat thinner) cap from side on, while the the lower tile resembles presumably Mario's cap from 45 degrees from his left. Interesting, huh? These look like they would fit on the titlescreen, but no other graphics remain of it, and the known beta titlescreen is quite different. Perhaps this is older than the above, or possibly something that was made for A titlescreen, but ended up unused, and were hence largely overwritten? The graphics are the same in the japanese release, unlike most unused layer 3 graphics… these are quite odd.
There was a signature here.
It's gone now.