I do not have proof. My mother, Eunice Mason Finley, daughter of Thursie Jones Mason, told me the family always said he was from Ireland. However, in the 1870 Census of Caddo Parish and the 1880 Census of Cass County, his place of birth is listed as NC.
There is also an Ephram Jones in Panola County, TX, Census of 1850 that is about the right age. However, his birth is listed as GA.
Uncle Floyd was one of my favorites. We saw him fairly often when I was growing up in East TX.