He plays a Gibson SG Double-Neck in the live version, but on the recording he used an acoustic for the begining, and a telecaster for the solo; I don't remember what the other guitars that he used for it were...

Ha, I found an old tab book: "Led Zepplin Early days" Says in here that he used two acoustics, one with 22 frets and a cutaway, and a regular 6 string acoustic. He also used an electric 12 string, and for the solo it says a 1958 Telecaster through a Fender Suproamp.