Re: appropriating melodies---it seems to me that there was a lot of that going around in 50s & 60s. Performers and groups would make a slight change in the melody, almost imperceptably, or rearrange or reword stanzas of P.D. songs and take credit for the song. I believe that many of the top acts often did so. I know that when I cross- refence the songs from my collection (I have 6 - 8 versions of some songs) that the performing group took a credit. His being in the biz, Sandy Paton could probably explain it better than I.

John