May be it would be worth ordering some earlier Wills (say Lydney/Newland etc) from the Gloucestershire Records Office between 1725-1780 to see what names are mentioned which would help solve this puzzle, but would have to decide which to order.

e.g

Will of James STEPHENS - 1728 - Lydney/Alburton
Will of William STEPHENS - 1781 - Woolaston

There is only one Will listed in Newland - Elizan STEPHENS - 1724.

At least with the Gloucestershire website, one can get an idea where the STEPHENS were located.

http://ww3.gloucestershire.gov.uk/genealogy/Search.aspx