Not fidng your James, but did find a will from the Abstract Wills of North Carolina 1690-1760 for Dobbs County of one
Feb. 8 1774 Mar 10 1774 Sons: FRANCIS MACKILWEAN my new plantation, also plantation called Old Ford on Contentnea Creek. John Stringer, five negroes and three horses. Daughters: Hanah , Elizabeth, Gatsey, mary, Elinor, nancy, Penelpy Mackilwean. Wife and executrix. Mary.
Possibly the great grandfathers of your James?