John: Seems like a good while back there was a thread here at Mudcat on this subject, but I can't find it. As I remember Blind Boy Grunt, aka Bob Dylan, and Lonesome Luke, aka Hank Williams, were among those identified.
I'm also finding that a lot of the old timey american country artists from the 1920's & 30's used several different names to do the same songs for different record companies - Grayson & Whitter had several incarnations.
Another thing the string bands did was use several names for the same fiddle tune, apparently to make their play list look more diverse. That's probably where the old saw, "They all sound like 'Soldier's Joy'" comes from !