The song probably dates back to the second World War when smuggling across the land border between British Northern Ireland and The Irish Free State, as the rest of the island was then known, was particularly common.

That last verse line should be "blessed our old faith" alright i.e. thank God we're back in the Catholic South!

Regards

p.s. An aunt of mine was a nun in a convent in Northern Ireland during the war. When visiting her family in Dublin, she smuggled bicycle tyres in one direction and butter in the other, on the train!