Hi Louisa Maud,
West Hanningfield being none too far from Sandon, I thought I'd advise you of a couple of families I have, the children were all baptised at St Andrew, Sandon.
Joseph Sewell married Mary Stowel 3 Oct 1777 at Sandon, they had nine children baptised 1778 to 1793, Joseph and Mary are my ancestors. Joseph was baptised 2 Dec 1755 at Gt Leighs where both his father and grandfather raised all their (known) children.
I would imagine there would be later generations at Sandon descending from Joseph and Mary Sewell but because their daughter Elizabeth married into my Warner family, plus time restraints, I didn't look for later Sewell families
A Joseph and Sarah Sewell had two children baptised at Sandon.
Patty 13 Dec 1785.
Harriett, "half baptised at home being ill" 27 Jan 1789 and received into the congregation 5 Feb 1789.
There could be others, I don't recall following up on this family.
I know these families are a bit earlier than you need at the moment but if you want any further details just let me know.
Regards.