I forgot to look at at George's records from Spotsylvania Co. I found one deed in which one of the witneses was Frans. Thornton Jr. George purchased 470 acres there in 1736, selling it in 1743.
Spotsylvania Co, VA Deed C: 206-207; dtd 4 Oct 1736; rec. 5 Oct 1736; Robert Slaughter of Orange Co, Gent, to George Doggett of Lancaster Co, planter. Wits. Thos Slaughter, Frans Thornton Jr, Frans Taliaferro.