Have you checked in DAR to see if the Thomas Martin is in your line?
I am a DAR member and decendent and found:
MARTIN, THOMAS
Ancestor #: A074565
Service: NORTH CAROLINA Rank(s): PRIVATE
Birth: 5-11-1756 BRUNSWICK CO VIRGINIA
Death: 5-13-1835 YORK DIST SOUTH CAROLINA
Pension Number: S*W21740
Service Source: S*W21740
Service Description: 1) PVT, CAPTS WILLIAM JONES, SHUFORD; COLS WADE, MCDOWELL, CAVALRY
2) ALSO SCOUT, COL WADE