Jack Campin in yur comments about DUBLIN IN THE RARE OULD TIMES you say;

"the narrator attacks one character for being both Black and English and hence not the sort of person who had any business being in Dublin"

Not in the lyrics I've known.

In this song, the singer is bemoaning the signs of change in his city, decrying the loss of the old ways and his inability or lack of interest in moving on in the new world.

I presume the verse you refer to is this one:

I courted Peggy Dignan,
As pretty as you please
A rogue and a child of Mary
From the Rebel Liberties
I lost her to a student chap
With skin as black as coal
When he took her off to Birmingham,
She took away my soul

How is that an attack on anyone? In a song where he's listing the changes to the in world in which he lives, he tells us that the girl he courted ran off with a student, presumably the singer is not a student. He tells us that the student had black skin, presumably that would not have happened in his father's generation, and that they went off to Birmingham. Where is the racial attack?