Hi Kenneth... I don't have much on your line of Elwood(Ellwood).I come from Isaac's Brother Benjamin line.I have a little of Isaac that was published from the New York Genealogoical and Biographical society if you are interested.
Isaac's father was Richard Elwood I(b.Abt. 1728 in Kent England d.Abt. 1754).We haven't been able to find much on him or when he came over from England.