Reviving this thread after the indignation at someone claiming to be acting on behalf of the Vaughan Williams Trust claiming copyright on an original setting of this song (as sung at our local Irish festival a two weeks ago).

My emails to the Trust suggest it might not even be related to them.
(Essential Media Group looks like it might be one of these dodgy predatory copyright firms acting on YouTube).

In any case, I recorded my own setting here.

Interestingly the tune 'Bushes and Briars' is listed for several early 1800s broadsides, but the 1905 book by RVW is the earliest notation I can find.

Easiest assumption is that Mr Pottipher was singing a melody that had been passed on aurally from the 1813 versions.