1Vernon Dotson, dotsonv at midwest.net.
One problem seems to be that Isaac wasn't mention in Caleb's will. It is possible that he had already received his part through the Kentucky connection. The rest of his children seem to have eventually ended up in Tennessee. I can place my Isaac near John Ward, Jr in Montgomery County. From you website, he was the son of John Ward, Sr and Hannah Petty.
The Dodson Book by Lucas gives Isaac's birthdate as 16 Nov 1774.