Jim, I have that same Gaylords album (the one with the cover you see on YouTube) - or at least I used to (not sure I still have it. That's where I learned (what I could of) the song, years ago.   It's nice to hear it again, now that I can speak and understand enough Italian to know what they're singing.

And you're so right about how hard it is to research the song, because so many other songs use that phrase. I do appreciate your finding and posting the info you came up with.

(If I can find my Gaylords LP it probably has the songwriter attribution on the label, but that would not answer the question of its early origins. I mean, I have lots of sheet music and recordings that list modern songwriters for songs that I know are derived from old "tradidtional" folk music or from classical composers (or both).