If the Ebenezer that left his will abt. 1796 in South Carolina refers to his "sister" Elizabeth, then this will must have been a son of Ebenezer that migrated from Augusta County into Berkeley County, South Carolina in the mid 1760's.
Ebenezer Sr. had to have been born sometime around 1725-1730, as he was old enough to receive a land patent on New River in Augusta County in 1752.He also received land on nearby Crabb Creek in 1754 from Col. James Patton.
He sold his land on Crabb Creek to Jacob Lorton, and his land on New River to Jacob Shell on the same day - 17 May 1767, but he had already acquired 200 acres of land in Amelia northeast on Santee River in 1764 [Source: "South Carolina Baptists", 1670-1805 By Leah Townsend, pg. 144]. He was referred to as "Ebenezer Wastcoat, late of Augusta County, but now of Berkeley County, South Carolina" in the 1767 Augusta land records, so he had clearly migrated to South Carolina shortly after his 1764 acquisition.
Several sources have Elizabeth Westcott (b. 1751) as a daughter of Ebenezer Westcott, Sr., so the 1796 will is clearly that of a younger Ebenezer, Jr.