Colin, back in the early 80s when Paddy Mallon was alive, he frequently copied all locomotive and wagon books for me at no cost and after I married and moved house I gave many of them to various Irish modellers around the country. His collection is with Louth County Council but they are vey slow at acting upon requests. A few years ago one of their archivists took the time to do A3 scans of the Omagh track plans from the GNRi Engineers Book and this cost me £25. Since this I have sent in other requests, and never got a response. Worth trying but Richard McLachlan has probably got whatever you are after anyway.