I have looked over the sheet music at the Irish Traditional Music Archive (Thanks to MartinRyan for the link!) and compared them to the Library of Congress version I posted earlier, and I believe the lyrics are identical except that "Hooligan" has been changed to "Fogarty" throughout.

—or vice versa, depending on which version is older. Is there any way to tell?

Why do you suppose they would make such a change—and not change anything else?

Also the (implied) songwriting credit is different.