Gary Murphy and I have been in extensive contact about matters arising from this thread. Since he and I were last in contact he has done a lot of work relevant to Benjamin Crowther (George Crowther's Dad, Aunt Euphemia's great grandad, and my great great great Grandad).
First, I have to confess I got a few things wrong. Benjamin and Sarah and family were in Leeds by 1841 (as Ben and Terry also discovered) . I had used the 1851 census date to determine that Benjamin was born in Birstall in 1790/1. The 1841 census suggests that he was born in 1795. Gary has persuaded me that the 1795 Benjamin is, in fact ours.
The Benjamin born in that year had a father called William, and its striking that there's evidence to suggest that he had other children - with names that were all given, also, by Ben to some of his children.
The other big booboo I made was in insisting on Benjamin being married to a Sarah Kitson. Gary has discovered that in the censuses for 1841 and 1851, there is a Ben and Sarah Crowther living at Staincliffe (near Batley) with a brother-in-law - George Kitson also in residence with them. It would be truly bizarre if there were two Benjamin Crowthers married to two Sarah Kitsons in the same area.
Garry has also found that, in Leeds, Benjamin's son - also called Benjamin - died in I844. There's also a death certificate for a baby boy called James in the same year. He died eight weeks old. On this certificate, Sarah's maiden name is given - Asquith. So this means that we should look for a marriage certificate for Ben. Crowther and Sarah Asquith. Sorry to have got this wrong.
Paul