In doing a scan on the Internet today I only just noticed your respone to my message back in June - sorry for the delay in getting back to you.
The person I am trying to trace is Isaac Dalby Fawcett of Killermine, Ballinasloe born 3 Apr 1821 died 22 Apr 1854 married Jane Araminta Fayle13 Jul 1842 Birr, Offaly (then Parsonstown, Kings County). I too have been unable to locate a place called Killermine, Ballinasloe! (maybe the spelling has changed over the years.
As a result of this gentleman the family still uses the middle name of Dalby the lastest being my four year old nephew. I have, however, been unable to go back any further that him. He was a Methodist preacher and family legend (unsupported I should add) is that the Dalbys were Hugonots. I suspect that his mother was a Dalby and his father a Fawcett.
I'd be grateful for any information you might have on this gentleman.