I've just had a look at Donal O'Sullivan. "Songs of the Irish", Dublin: Brown and Nolan, 1960. Príosún Chluain Meala is included, with musical notation, Irish Gaelic words, literal translation, poetic translation - which is attributed to J.J. Callanan and background notes. From the evidence of the song, it is the story of a lad named O'Donnell, thought to be one of the Whiteboys, of Iveragh Co Kerry hung at Clonmel Gaol.