As discussed earlier in this thread, the tune is traditional; Padraic Colum re-wrote the words at one point (I don't think that Percy French had any involvement) and most people who sing it nowadays are singing the verses as he re-worked them, with the exception of the "dead love" bit.  I've heard the misprint story and while it's obviously possible, I'd want to know which book it was!  I've suggested elsewhere that Margaret Barry was the most likely source of the change to "dead love", and have since found that "Songs of the People" makes the same suggestion.  Margaret Barry is the original source, so far as can be told, of pretty well all the "revival" recordings of the song, which are not so much versions in their own right as arrangements of her version.

Malcolm