I was looking for completely non-DC related free sheet music the other day, and I chanced upon this website...Words3Music.ph. So I start looking through their list of artists, and lo and behold, there's DC! They have DC's arrangement of ABMB, but that's it at the moment. It doesn't look that bad in terms of difficulty (I have only ever played percussion, so I only had to read actual sheet music when I played mallets...therefore I am not very good at reading music...so I'm sure you piano players will have no problem with it), and it seems pretty accurate to me, from what parts of it I've beena ble to play.
Sheet MusicJust go there and scroll down to DC...it's alphabetical order.

ETA: They also have I'll Be by Edwin McCain on there.