I think (95% sure, I'd say) I learned it as a kid from Dick & Beth Best's 1954 (my birth year) edition of Song Fest, where it appeared with no attribution or copyright notice. The info on the Digitrad copy (which I first saw only a few months ago) was the first hint I ever had that it was neither anonymous nor in the public domain. I'm going to do a little independent research before updating my page in that regard.

Liland