There's 2 songs about Coburn in James N. Healy, The Mercier Book of Old Irish Street Ballads, vol.3, "The People at Play", pp. 93-96, namely "The Cowardly Englishman" (begins "You gallant sons of Grania, pay attention for a while") and "Coburn's Challenge to Heenan", beginning :You gallant sons of Paddy's land I hope you will draw near".Does this help??