John Moulden seems since then to have become more certain that McGarvey was indeed the writer, and that's good enough for me. A form of the tune appears as Gilderoy in the early 18th century, but may perhaps be earlier. Simpson (The British Broadside Ballad and Its Music, 1966, 252-4 and 109) points to a tune appearing in the mid 17th century, The Clean Contrary Way, as likely ancestral to Gilderoy and Dives and Lazarus (a close variant of which last was used in Ireland for My Love Nell, and later for McGarvey's song).