It's a song that's interesting in view of the Good Friday Agreement having ended the policing of the border between the six counties of Ireland still ruled by Britain (Down, Antrim, Derry, Armagh, Fermanagh and Tyrone, or Dada Ft, as the mnemonic goes) and the 26 countries that comprise the Republic of Ireland.

Here's the Shadow Foreign Minister in Britain talking about the border problem.

In the song, the Free State farmer (which is to say a farmer living in the independent Irish Free State that existed before Ireland became a Republic) is determined not to pay tax for buying his suit 'abroad' - on the Derry side of the border - and so disrobes himself on the train home to Inishowen in Monaghan (in the Irish Free State then; in the Republic of Ireland now) and dresses in his new suit…

It's kind of like the people who get around Ryanair's ridiculous luggage rules by dressing in five layers of clothes, waddling on to the plane and then disrobing down to T-shirt and shorts.