I have William BROOKS and his wife Mary SMITH (married 1843) living at Saffron Walden. My line goes through son William (b 1851) who probably never went near London although I can't find him in the 1871 census. However, most of his brothers and his sister - Thomas John (1845), Joseph (1847), Alice Louisa (abt 1855) and Frederick (1857) went to London.

I haven't followed up on these brothrs and sister.