Hmmm, maybe we're not talking about the same James.My 5 x great grandfather is James Willson (1715 -1809). He married his first cousin Rebecca Willson in PA in 1750; they then moved to Rockbridge Co (just south of Augusta) and had 13 kids.
Some of the names you listed looked familiar, but looking back over my tree, there isn't a George. Also, the Samuel that I have died in 1833 in Logan County, KY--not in the Rev War.
But, going backwards, my James' father was Matthew Willson, who never made it to America because he was lost at sea en route. His father was Robert Willson, who must have come at another time because he did make it over to PA. In fact, Robert went to Augusta Co and died in 1745--the year that the county was created. His will is, I believe, the first will in the Augusta Co records. (see Chalkley, volume 3).