Re John Snr born at Sea.
Have you followed up the Nephew William Chirsal age 18 on the 1851 Census with the Family?
Down as born c 1833 Stanclia, Gloucestershire , looks like Standish to me.
1861 has a William CLISSOLD born c 1831 Standish
William Clissold, 30
Eliza Clissold. 31
Theodore Siff, 9, Stepson
Walter Siff, 6, Stepson
Mary Clissold,2, Daug
Marriage Reg;
William CLISSOLD, June 1859, Strood, 6a ****
Looking for a Eliza;
Eliza PIFE, June 1859, Strood, 6a 524
1841 in Standish we have;
Richard Clissold 35
Betsey Clissold 35
Jane Clissold 12
WILLIAM Clissold 10
Anne Clissold 7
Samuel Clissold 1
1851 William is not at Home
1851;
Richard Clesaols 48
Elizabeth Clesaols 46
Hannah Clesaols 17
Eliza Clesaols 8
George Clesaols 5
Charles Clesaols 2
1861;
Richard Clissold 58
Elizabeth Clissold 55, born Tetbury
Eliza Clissold 18
George Clissold 15
Charles Clissold 11
Alfred Clissold 8
Cant find a Marriage but it is possible Elizabeth is nee KING.