Just as you say Ray. I got the wrong end of the stick. Meanwhile Dave your tune is indeed a Folk tune, and the radio gleaned song has one foot in the Tradition, it could become a super variant or be transformed.
Down in the fields, and Buttercup Joe were both on 78rpm recordings and both firmly in the repertoires of Traditional singers. The closer you get to Folksong, the further away it flees. My view is don't worry about it, as Martin Carthy said to me many moons ago, 'Go with your heart'. It works for me.