Breathnach used the Princess Royal as an example of Bunting ltering tunes. I left it out of the quote I posted earlier but this is what he said:

'Buntings treatment of Carolan's well-known air The Princess Royal illustrates the point. He noted the tune from Arthur O'Neill, the harper, and published it the 1840 vo9lume (p.35). There it appears in the key of Fminor (four flats), a key in which O'Neill could not have played it. In the sixth bar (and elsewhere) Bunting makes E and D natural, since the harp had not the extra strings required for playing accidentals. It is interesting to note in the version published from Bunting's own manuscript in O'Sullivan's Carolan (I, p. 210) that D is not raised at all and E only when preceding the tonic.'

And there we get back to the earlier quote where BB states: 'In effect, what Bunting did was to alter the melody to fit what he considered to be the correct and suitable harmonies.'