I couldn't find an Australian version in Steve Roud's folk song index. In the index the song is #490, (Laws L12) and he indexes about 87 traditional versions (under a large number of titles), mostly from England and the USA and Canada, several from Scotland, and 1 or 2 from Ireland.

He gives "The Wild and Wicked Youth" broadside the same number, but "The Jolly Blade" and "The Flash Lad" broadsides, although in in his broadside index, do not have numbers, so he didn't associate these two with any versions of the traditional song, even though Barrett's "The Flash Lad" is in the folk song index. I think this is probably a mistake, but comparison of each traditional text with each broadside, keeping tack of sameness and differences, would be a formidable task for this song alone, and clearly can't be done for such a huge index. That would be a good project for a separate study.

The Bodley Ballads website also has a copy of "Valentine O'Hara", but I coundn't find "Allan Tyne of Harrow". This looks like it may be distantly related to "The Newry Highwayman", but it isn't his sweetheart who betrays him, and the ballad opens with quite different adventures than "The Newry Highwaynman"