Ballyfin House was included in the National Inventory of Architectural Heritage (NIAH) survey of Co. Laois, carried out by Duchas around 1999 and published subsequently. Most local libraries should have copies of the book, which comes with a cd of images. Otherwise it’s available in bookshops.
I think the images are on the NIAH website, which is at http://www.buildingsofireland.com (I think- maybe .ie?). If not, there should be a link from the DEHLG website, at http://www.environ.ie
If memory serves, one or both of the Morrisons had a hand in it, which means it’s probably included in the book on them published by the Irish Architectural Archive (and written by Edward McParland?).
I just checked the http://www.buildingsofireland.ie site, and it appears that Laois was never published. This is a pity, and surprising, as when I left my job there in 2001 it was sitting in cardboard boxes ready to go. Now why did I leave? Oh that’s right…
Sorry if I got your hopes up.
Maybe if you contact the NIAH office directly they could help. The material is certainly in existence.