Hi Sandie,
I've searched Hull 1861 census for your Grunwalds couldn't find Saul.
Could this family be of relevence.
2 Valence Place, Humber Ward, Hull.
PRO REF RG 9, Piece/Folio 2587/027v.
Jacob Grimwald/ Head/ M/ 32/ Tailor/ born, Laifte Hirhessen, Germany.
Eliza Schille Grimwald/ Wife/ M/ 31/ Tailors Wife/ born, Laudenback, germany.
Louisa Grimwald/ Daur/ 2/ born, Hull, Yks.
Regards kooly...