I doubt if I can add much help to your search, but my great grandfather's name was Patrick McCloskey. I believe he is the same man who was schoolmaster at the abandoned "thatched chapel" at the townland of Cashel at the time of the 1834 Ordnance Survey. My wife and I visited Dungiven in 1997, but were unable to establish any documentary proof while we were there. I had known that Patrick was a schoolmaster before he left Ireland, that he had married Anne O'Kane and they had had two children: Alice, born @1835, and Thomas, born 1838. They all migrated to America @ 1839 and had seven more children, including my grandfather, Joseph, born in Maryland in 1846. They moved westward to the Pittsburgh area about 1850, and settled in the town of Port Perry, a few miles upstream from Pittsburgh on the Monongahela River. Patrick was a "distant cousin" of John McCloskey, owner and operator of coal mines and a steamboat business. I believe that John was connected with the New Orleans McCloskeys, since Port Perry was the northern terminus for riverboat travel on the Ohio and Mississippi Rivers. My father never claimed any family connection with Archbishop John McCloskey, but my dad was born in 1884 and was baptized John Cardinal McCloskey, thus named for the archbishop. I was named for my father and was John Cardinal McCloskey Junior until I dropped the Junior when my mother died. Since Patrick McCloskey taught in the abandoned chapel at Cashel, I strongly suspect that he was of the McCloskey line that had served as erenach of church property around Dungiven and probably furnished many of the McCloskey priests who served Dungiven Parish during the Penal years. Since Patrick and Anne named their first-born son Thomas, I wonder if he (Patrick) could have been the son of Thomas McCloskey who resided in Crabarkey at the 1831 census. If you should uncover any evidence to support or disprove any of my assumptions, I would like to hear from you.