I didnt know him - but a friend of mine did. Davy (Graham) used to mention him as a visitor in 1962/3 to the flat he was sharing. You probably know he called a blues instrumental from his 1963 LP Guitar Man "Blues for Geno"
Incidentally, the song you were referring to earlier is the Champion Jack Dupree number "Junckers Blues" from 1940.
Incidentally, this blog is a great read - a lasting tribute to someone who was truly living in interesting times !