The tune sounds like a Lloyd adaption of that used for Master McGrath. He used Colm O'Lochlainn a couple of times. Bold Lovell is a good example (See COL version of Whiskey in the jar). The McGrath tune in its turn is Erin-go-Bragh. I expect you could trace it again to an Irish language tune or song. Modern Folklorists do find their patience exhausted by Bert's activities. However as Roy Palmer once said to me 'Would you rather have that song or not?'. I know my answer.