The reference to Nathaniel McIlhago is new to me, and brings on to the clan scene an 18th Century farmer of whom I have not heard before. Can he be identified with anyone else? From a date perspective he could be Nathan(iel) McIlhaggar, born about 1758 in Carnmoney, who married Betty Burney (born about 1762) in about 1783 in Carnmoney. At the marriage of their eldest son, Nathan, his father's name is recorded at Nathaniel (McIlhagga), so we do have a first name identification. If this is correct then Nathan Sr. would only have been 12 in 1770, which throws doubt on whether we have the right person, though of course he could have been born earlier. If the Nathaniel of Ballytober had been a tenant at, say, 20 years of age, then this would push his birth date back to at least 1750, giving him a marriage age of 33. We have to add that we have no evidence that Nathan McIlhaggar of Carnmoney ever left that place in order to farm in Island Magee, and he certainly married in Carnmoney.
A second approach to placing Nathaniel McIlhago is to start from the fact that clan members certainly farmed in Ballytober at later dates, and that they were men who spelled their name with a final 'o'. James (Junior) McIlhaggo farmed in the townland in about 1830, as did his son William after him. Was this therefore a long established family tenancy, presumably after Nathaniel McIlhago had reapplied for it in 1770? James (Junior)'s father was James (Senior), also a tenant farmer in Island Magee, perhaps in Ballytober, though we have no proof of the townland. He was born about 1755 and appears to have had an elder brother, Samuel, born between 1740 and 1750, who had a tenancy in the townlands of Ballylumford and Carnspindle. Ballytober is adjacent to Carnspindle. So perhaps we have now found the name of Samuel and James' father, which up to this time we have not known, namely Nathaniel. I admit that alternatively Nathaniel McIlhago could have been a sibling of Samuel and James, but on balance my preference is for 'father' as there is no reference to a Nathaniel in documents relating to the lives of Samuel or James. This would give Nathaniel McIlhago, listed in the 1770 Belfast Newsletter a possible birth date of 1720-30, which would have made him about 50 years of age in 1770.
I have quoted William Roulston's article in the 2005 Directory of Irish Family History Research, Ulster Historical Foundation, with permission.