Regarding the Tiffins, I've just checked what I've got in my tree. The
1741/2 will of Thomas Tiffin of Layer-de-la-Haye led me to Earls Colne, and the mighty Earls Colne Database has the baptisms of Thomas' children by his wife Anne. Amongst those children was John Tiffin, baptised 1690, buried 1752. His wife was Sarah (maiden name currently unknown as I haven't found their marriage yet).
There were eight children of John and Sarah. There's a baptism for a son John in 1720, but he'd be too old to be Sarah Whittaker's husband (he's 30 on the marriage licence in 1762. Of course, the age on the marriage licence might not be accurate). There is a gap though in the baptisms of John & Sarah's children in Earls Colne, about 1732, which might mean that Sarah Whittaker's husband is their son.
One of their sons was Charles Tiffin, baptised Feb 1736 according to the ECD (I suppose they mean 1735/6), and I think he's the husband of Mary Rayner, and was the witness of Edward Wade and Elizabeth Cardinall's marriage. But the very fact that he's connected in that way, makes me wonder if John Tiffin is his brother (or cousin? After all all Charles was the grandson of Thomas Tiffin of Layer-de-la-Haye).