The original image of 1931 for the Robinson family also includes Hannah Caven, mother to Elizabeth.
One odd thing is that Harold and Elizabeth apparently a daughter Margaret born in 1923. No record of her in the 1931 census entry, only sons Harold,13 and Walter, 4, show then.
www.findagrave.com/memorial/144734428/margaret-h-brangham Only sons Harold,13 and Walter, 4, show in that entry.
I am not sure about this Robinson family and how it connects to Harry Hussey. Is there no more within the family stories that suggest a link that could help you? Do you know why the family belives that he was brought up as a Robinson? In many cases where a child is brought up by an adoptive family from so young, it is all they know and are happy to go by the adoptive family's surname. Why would he in later years have chosen to revert to Hussey I wonder.
Monica