I think "The Mero" is a place in Dublin. Within the text there is a reference "Bang, Bang shoots the busses with a golden key". I was once told by someone from Dublin that Bang, Bang was one of Dublin's street characters. He had suffered some form of mental illness (probably shell shock) during the First World War, he had been decorated and been given the freedom of the city of Dublin (the golden key). He was to be seen on the streets of Dublin shooting at the busses with his key, in the same way that small boys used to do with sticks while playing "cowboys and indians", up until he died (I think in 1957).
All the best, Bill.