The acoustic part is a separate song on the Waitin' For the Surf EP.
PolloGuitar
I wonder if it's an alternate take from the original session.
Good question. I can't find my copy of that best-of at the moment, but I remember the liner notes being pretty detailed ... and I'm not sure they had a keyboardist in the band at the time of that EP, but I could be mistaken about that.
—That was excessively violent and completely unnecessary. I loved it.