Never saw Ritchie Havens do it, but considering he used thumb for so many things he may have. It really has everything to do with Josh Sr.'s treatment of #12 Train, John Henry, and a few others in E.

He was my favourite guitarist and I've always put double pickguards on my various axes over the years in tribute to him. For many years he played Martin "New Yorkers" and then became the first player/endorser for Ovation. At least a year before Glen Campbell.

Rick