Don't mean to rehash old back and forth but in light of recent internet info... It seems to me, that despite how some folks may have co-opted the term, "Hootenanny" and including the changed spelling of the term, the originator of the term deserves the right to any royalties which may result from its use. Today I found a post about Texas Jim Lewis which indicates that he had been performing since the late 1920s and was using the term since the mid 1930s to refer to his percussion/sound effects gizmo.

Texas Jim Lewis

"The Hootin'nanny

It was also in 1936 that Lewis's band signed a deal with Vocalion Records and one of the three 78rpm records that they cut for the label -- "Who Broke the Lock on the Henhouse Door?" -- featured the recorded debut of the bandleader's unique musical contraption, the "Hootin'nanny." A crazy assemblage of assorted brass automobile horns, whining hand-crank sirens, percussive clackers, two washboards, a blank-firing gun, et cetera, the "Hootin'nanny" became one of Lewis' enduring trademarks -- especially after it was seen in use in the 1937 Vitaphone movie, Stuck On the West.

The "Hootin'nanny" also appeared in some of the 41 additional films..."

Knowing that he had to have developed his Hootenanny long before he was recording with it, or being featured in films with it, I'd say that he most definitely has the earliest claim to the term.