It would seem very likely as suggested above that the G was actually a figure 9 which looked like a lower case G.

The nine string that Joe adapted himself from a six string was according to him the result of getting pissed off with people asking to borrow his guitar. He thought that adapting it this way would stop them asking. Whatever the truth of the matter in Joe's "rediscovery" period he always played a nine string.

Surely you blues experts out there that keep telling us where to hear and where and how to play the blues knew this already, it's all out there for anyone with a real interest in the real thing.

Hoot