Love it, Joe!!
I am told (and do not recall who told the story; an Irish-American singer who sings it "Aragon") that some years ago Si Kahn's son was in Ireland, and with a companion passed a pub where "Belfast Mill" was being sung; he commented on it and his companion reportedly told him, "That's Belfast Mill, a traditional song in this part of Ireland."
I don't know if the story is so, but there is no doubt that Si's song has truly become traditional.