George Caleb Willmott/Willmouth of Woolwich, Kent, England

I am researching the descendants of George Caleb Willmouth (b. c1790) both in England and Michigan, USA.George is my g.g.g.grandfather and I am still searching for his birth and death.Five children of George & Elizabeth Phillips were christened between 1817-1829 at St Mary Magdalene, Woolwich, Kent, England under the various names of Willmott, Wilmot, Wilmuth and Willmouth.Elizabeth's first child was born at Milton-next-Sittingbourne,which is also the mother's birthplace, as given in the Woolwich 1861 census.
I am looking for any siblings of George Caleb Willmouth under the variants of Wilmot, etc.George was a Waterman, so may have originated from along the Thames riverside.
One of George's sons, also George Caleb Willmouth b.1817, immigrated to Michigan, USA in 1860s.Some of his family are missing and I am looking for information on his son Joseph James Willmouth b.1857 in Woolwich, and his grandson George Alfred Willmouth b.1880 in Detroit, Michigan.They may have used the variant "Wilmot".
I would appreciate any help in tracing these ancestors.