There appears to also be the matter of Isabella Pyne/Caldwell. She married the Rev. Samuel Buxton Smyth in 1870 (his second marriage) under the name Isabella Pyne, and they are in East Hanningfield in 1871 (information from the other thread). I suppose her marriage certificate will just give the same, though...
She's visiting Ellen E. "Easton" in 1881 (actually Easson) - but she was nee Atkins. I had a quick look at the other visitors but couldn't see any connection there.
A look at the original christening records from Chelsea would be helpful as they should say what "John"'s occupation was.
I wonder if there's any connection to Isabella Deedes Pyne, b. 1 Dec 1828, chrs. 11 Aug 1829, St. James, Paddington, illegitimate daughter of Mary Ann Pyne?
Where did the marriage of George Caldwell and Mary Ann/Marianne Pyne take place in 1843?