I have a copy of a 1946 songbook, "K6 Wranglers Present the Jack Guthrie Song Book" ...
   The page on Jack Guthrie begins, "When Jack Guthrie wrote "Oklahoma Hills" he wasn't indulging in the usual idle fancy of the members of the song writing profession. Jack actually hails from the hills...."

   Question: What changes, if any, did Jack make before he copyrighted his cousin Woody's creation in his own name? Who would know?