Ryan- I'm also trying to patch together this Gibb family tree and I think were close.The info I have is the previously mentioned David Gibb Jr. (died 1842) was the son of David Gibb Sr. whose wife was Mary Elizabeth Gibbs, daughter of William Gibbs.I'm not sure how the "Hamilton" part you mentioned fits in. The family tree I have goes as follows:
David Gibb Sr married Mary Elizabeth Gibbs (dau of Wm Gibbs) Sons: David Jr. and Joseph David Gibb Jr. married Margaret Sisley (Sisnee?)and they had 12 children. I have most of the tree figured out from there.