Quite the surprise to see my name in blazing headline :) It compelled me to get onto this right away.

The biggest news for me is to discover that I've been wrong for years in my thinking that my many-times-great uncle John G b 1718 son of John G & Mary Cotteen is the one who married Catherine Killey in 1739. Frances pointed out that this marriage states Balmillaghyn. Furthermore, the children starting with John in 1740 match well to the 1812 will of JG of Ballamillaghyn. So I'm back to the drawing board on "my" John.

I'm confident, as you are, that their son John b 1740 is the one who married Margaret Quilliam 1763 as they are from Ballamillaghyn when they were buried (he 1829 age 89, she 1822).

However, I disagree that their son bp 1764 is the one who married Isabella Cavendish. Instead, I think that their son married Elizabeth Oates in 1787, and had a large family though most died before the parents. Both of these folks appear in 1841 and 1851 census's and died at great ages in the 1850s with Ballamillaghyn mentioned in their burial entry.

Regarding Isabella Gelling (Cavendish), there is an Isabella Gelling in the 1851 census at 4 Shaws Brow in Douglas, age 84 Widow born England, with Elizabeth Gelling granddaughter Unm age 26 DressMaker b Braddan. This likely matches the Isabella Gelling buried 2 Feb 1856 age 89 on Brian's website. There is an 80-year old Isabella Gelling in the House of Industry in 1841 census.

I'm with Frances that it's unlikely that a 17-year old boy would be the JG marrying Catherine Killey in 1739, though he must have been quite young. He died some 73 years after he married, which must be some kind of record for that time. The burial entry on Brian's site says "90" but I'd be happier if he was 93-94 range, which was the age of his wife when she was buried in 1806. I haven't searched thoroughly but so far we don't seem to have a good matching baptism ca 1715-1718 for him.

I can't help you with the Ann Moore question. However, I think it's quite plausible that the Ballamillaghyn line goes back to a JG and Margaret Kneale, but I haven't checked that out yet.

Unfortunately my genealogy database has strangely disappeared off my PC. I can't check anything more until I get it back again from my backup.