I too am looking for info on McCombs from Mecklenburg Co in 1700's. I have a Samuel McComb (b.1736 d. 1798 m. Mary Archer.) The McCombs and Archers were to have come from Rockbridge Co. VA. They had a son Samuel McComb (m Jane Emerson). Samuel and Jane's children are Samuel (b.1789 d.1848 m.Alice Brandon), James (b.1797 d.1841), Mary,
Robert [b.1797 d.1854 m.(1)Sara Huson m(2)Mary Camilla Sanford]

My husband's line is through this Robert and Mary Camilla Sanford. They lived in Milledgeville, Ga. I don't know of any connection with your family, but it seems a possibility. Would be interested in any more info you have. I have info from Robert and Mary on down.