BUT in the 1861 census they appears as COCKSHULL - living at 37 Orford Street, Chelsea:

THEN their children also have COCKSHULL on their birth certificates:

Emma COCKSHULL born 11th February 1852 & William Thomas COCKSHULL born 31st October 1853

Parents John Thomas COCKSHULL & Elizabeth COCKSHULL (formerly CALLAN) !!!!!

The question remains :

Was the COCKSHUTT notation on their marraige certificate a one off mistake

OR is the COCKSHULL notation thereafter wrong?