I can't help with info on Garwood but that was a very important book for me and your statement that "A look at the tabs showed them to be well written and very clear and easy to read." is right on the money. I think I learned all of the John Hurt tunes in it including Candyman and Frankie (which is the first tune I think I ever became obsessive about learning because I loved it so much). It also had a good discography that got me going on my country blues LP collection.