Like @brookdalebill mentioned, John Denver used the Guild 12 String, but a VERY prominent user was Tommy Smothers on the Smothers Brothers TV show. I vaguely remember a few rock players in ads for Guild electrics....don't know if they actually played them. (I have a memory, maybe false, of Zappa promoting Guild electrics. The picture had him holding one under his chin, like a violin. Anyone?) A guy I knew in early seventies had a Guild "SG"-type.....it came from factory with NO FINISH, just raw wood, sanded very smooth. Only one of those I ever saw.