Sarah: I have no proof that Zachariah and John C Traywick are brothers -- only that both are listed in the 1880 census household of Berryman Traywick (cir. 1806-1880) as grandsons. My research into the Traywick family is still early.
John Caleb Traywick is listed as father on the death of Samuel Traywick (with Lenora Newton listed as his mother)
I would very much appreciate your sending me a copy of your Traywick spreadsheet.