Is the Robert Penfold you mention on the 1901 census born 1863 and married to Mary Ann (1865) children Emily, William, John, Rose & James? They are at 19 Wilford Rd, Croydon. Robert is a Hawker.
May not be the same ones. The ones above are related to the Lanes, Smiths, Gardners etc. but not sure about the Williams.