Hi Trevor,
I had a another look at the Fortescues you mentioned that were from Little Coxwell, Great Coxwell and Wantage.
I assume you may already have this info, however -
The James Fortescue born in 1736 in Great Coxwell would only have been 15 years old if he was the one married in 1751 to Elizabeth Hazel in Uffington?
There was a Thomas Fortescue christened on the same day as his brother John in Faringdon on 14/10/1758 - maybe twins (or they just saved up and went to town to do both on the same day?)
John Fortescue and Sarah (m. 1780 in Wantage) had Anne and Jane (both Christened on 22/1/1787 - twins again?), and Sarah (1784) and Elizabeth (1781)
Cheers,
John