Is there any evidence that this family in Northants/Hunts were anything but the established church? John and Rachel baptised possibly their first child in the established church, but we don't know about the Sawtry children. If they were married in a Quaker ceremony then I very much doubt if they would have baptised children in the CofE. The Quakers were a very insular set of people.
Equally I don't buy Huguenots turning into Quakers, although I'd be happy to be proved wrong.
But you've got a long way to go Dave before you need worry about whether or not they were Huguenots.
Yes Sandy, I'd checked Lewis as well in Hunts but drew a blank. I still think the name might have been corrupted in the parish register, but 30 fiche with 70 pages per fiche is too much to contemplate ploughing through with a magnifying glass!
David