Can't help with the train Michael - but here is a song with a similar history.
During the Irish War of Independence there were many hundreds of songs made by local people and referring to incidents such as your train. Because of their local nature, they never made it out of the localities where the events occurred; I reckon we must have recorded around a dozen, some of which were made in the lifetimes of the people who sang them.
I am convinced that there is great scope for a published collection of these local songs, especially as, quite often they are the only record of the events having taken place.
This is one we got from a West Clare man living in London. He vaguely remembered the incident and the first appearance of the song.
It refers to the activities of local people who, while they weren't part of the Independence movement, supported the aims. It became a common tactic to pile a bundle of paraffin soaked rags up against the doors of RIC barracks (police stations) and set fire to them - more for their nuisance value than anything else.
This happened in Quilty, County Clare, around 1921; so far we have never found anybody else who remembers this particular incident taking place.
Thanks for the interesting question - and the song.
Jim Carroll   

THE QUILTY BURNING.         
Sung by Mick Kelleher.

Oh the burning of Quilty, you all know it well,
When the barrack took fire where the peelers did dwell,
The flames bursted out, sure it was a great sight,
There were women and children out there all night.

Michael Dwyer, sure, he got a great fright,
He called in his wife for to rescue his life,
His daughter ran out and she roaring, avore,
Blessed light, blessed light, keep away from our door.

Liam McCoy Kenny, looked out through the glass,
He saw Patsy Scully outside at the Cross,
Oh Patsy, Oh Patsy, take out the poor ass,
For the whole blessed place it is all in a mass.

Michael Dwyer, he came down on the scene,
He went down to the cross and called up Jack Cuneen,
My house will be burned before 'twill be seen,
And my fool of a son is above in Rineen.

Then Paddy Shannon thrown out his old rags,
He stuck his poor missus into the bag,
The burning, the burning, it started too soon,
'Twill be burning all night until next afternoon.

Then Paddy Healey came out in the flames,
He could see nobody there but the peelers he'll blame,
He went into Tom Clancy and told him the same,
By damned, said Tom Clancy, 'tis now we want rain.

Father McCannon came down to the gate,
He says to the boys, there's an awful disgrace,
For this old barracks is an awful state,
It's no harm to be banished and gone out the place.

Now to conclude and to finish my song,
I hope you'll all tell me my verses are wrong,
For this old barracks is no harm to be gone,
For many the poor fellow was shoved in there wrong.