I've seen 1960s pictures of Spider John Koerner with a National and also with one of those Gretsch flat tops with a plectrum-shaped soundhole. I've also seen photos of Rambling Jack Elliott with one of those. Does anybody know what that model Gretsch was? Some of SJK's 1960s records do sound like a National, but others don't. These days he seems to have a 12-string. There's a photo of Koerner Ray & Glover with Big Joe Williams, so maybe that's where he got the idea of adding octave strings from?