Nibs,
You are in a good county for Niblocks. I had a Miss Niblock marry my James Harrison of Church Hill, County Monaghan, Ireland. He was born about 1730 and married four times.
Church Hill is still in County Monaghan and the Province of Ulster, and is today in the Republic of Ireland, not Northern Ireland. County Monaghan is one of the three Ulster counties that stayed with Ireland; six counties of Ulster went with Northern Ireland.