If he was married, look for the place where his wife and family lived, look at the map (the ordnance survy old maps for Ireland are on osi.ie) and find the nearest barracks, go onto the National Archives Ireland site and browse the census for the county/DED/road. It will show where all the initials start. If you click onto one it will come up with the list and you should be able to look at the original which will be a form H. This was completed for soldiers and the constabulary. This return will also tell you whether he was the son of a policeman as there were different entry requirements if you were. Hope this not too late, have only just joined Rootschat and saw your post.