Having listened to the Ros a' Mhíl sample, I recognise the from the verse beginning "Is buachaillín deas óg mé" that the one in question is generally called "bóithrín Ros a' Mhíl" in speech (from the last line of that same quatrain ) to distinguish it from the other songs rather than imply the song is about the bóithrín. Was there a version in Ceol na nOileán? Just a hunch. Wouldn't be surprised if Ceaití was there too but not so sure how "classic" a text it would be.