If you were talking about your ancestors there in the early 1600s I'd say they would most likely have been Puritans. John Winthrop's estate was in Groton and that is only some 18 miles from Theltenham. The general area was heavily Puritan in those days I think. I don't know much about the Quakers in England in the mid 1700s. Also, I believe the Puritans faded away after 1700. To take a guess, I'd say they probably weren't Quakers but it's only that, a guess. My Ong ancestors were from Lavenham, Suffok, also in the area and their proximity to Groton and the time of their departure, Dec. 1630, make it highly likely they were Puritan emigrants. Even so, some people with special skills who weren't Puritan emigrated with Puritans.
My people appear to have adopted Quaker beliefs in n. New Jersey c. 1700. I doubt they did so before.