Moira,

FWIW, I learned it as a traditional song also.

That may or may not be a real indication of its origin, unfortunately. For example, a lot of people think 'The Scotsman' is a traditional song, too, even though it's not. I've even had my own work sung back to me as 'Trad' before. I guess the moral of the story is that we, as folk musicians, need to make sure we give credit where it's due - Which it sounds like you're trying to do! :)

Good luck in your quest! - Ian O'Donnell