Update to my original request...a success story!

Since my last post I have determined the following details:
George Graham Gibson was actually born William George Graham and his father was Ellen Moore and George Graham. More specifically:
Ellen Moore married a man named George Graham in the Coleraine Presbyterian Church ( Terrance Row Third Presbyterian Church) on 14 October 1889. They then had a son George Graham - my grandfather. I have still not been able to find a baptism for him but I am pretty certain in was born in Dervock, County Antrim, Townland Urbal - old spelling - Orble. George Graham jr's birth date is supposed to be July 12 or 13, 1891. Now I need to contact the Dervock Presbyterian Church to see if a William George Graham or a George Graham was baptised around this date in 1891.
I then find Ellen Graham emmigrating to New York in Fall of 1893 with her son William George Graham (age 2 yrs). She then marries a man named Alexander Gibson in 1895 in New York City. They have a daughter together named Evelyn in 1898 (Evelyn goes on to marry a man named Sydney Prior). Ellen Moore indicated her marriage status on this marriage certificate as widowed - no idea when George Graham (first husband) would have died in Ireland. So George Graham must have taken the last name of his stepfather Alexander Gibson very early on in life and kept for the rest of his life.
Ellen Moore then marries for a third time in 1931 to a man named Thomas Brown. I actually was able to obtain copies of both marriage certificates (i.e. 1895 & 1931) from New York City which confirmed I was dealing with the same Ellen Moore. She dies as Ellen Brown in 1944.
I also found out Ellen Moore's parents were Daniel Moore and Ellen/Ellin White who married 19 September 1859 in Ballymoney, County Antrim. They not only had Ellen but then also had at least 3 sons: James Moore born 30 Sept 1868 in Dervock, Ballymoney, County Antrim; William James Moore born 2 Nov 1871 in Bushmills, Ballycastle, County Antrim; and Robert Moore born 23 Aug 1874 in Busmills, Ballycastle, County Antrim. If there is anyone who might be connected to any of these individuals and you want to compare notes, I would certainly be interested.
Thanks to everyone who helped me out with this genealogical brickwall. Once I looked at the problem a little differently, the bricks came tumbling down quite quickly.
Cheers,
thecouch