[Janet]

Thomas's son James is a Coal Agent in Sutton on the 1881 census age 26 and born Sutton, then looking back at the 1871 he is age 17 and in Sutton with parents Thomas 51 Cotton Sizer and Farmer born Sutton, and Mary Ann 51 born Sutton. Thomas and Mary Ann's eldest son on the 1871 is John age 24, i.e. born 1846-7.... In 1861 Thomas and Mary Ann are at Sutton both aged 42, and in 1851 still at Sutton age 32.

...you would be best to work back one step at a time with certificates to make sure you follow the right people

Yes, thank you, thank you! I think we're looking at my family here. This much I am fairly well assured of: my mother's father is this Walter on the 1881 census in Sutton:
James BERRY Head M Male 26 Sutton, York, England Coal Agent
Emma BERRY Wife M Female 27 Sutton, York, England Housekeeper
Walter BERRY Son Male 6 Sutton, York, England
Maggy BERRY Daur Female 2 Sutton, York, England

Your advice is quite right, and I suppose that I really should not skip any steps at all. I should start not with James' birth cert but with Walter's and see what is there. That will tell me what his father was doing at the time of Walter's birth, and also will confirm his mother's maiden name. (I think that is where our Pickles relatives come in. I am pretty certain she was Emma Pickles.)

Come to think of it, do you think I might be missing out by not hunting up my own mother's birth cert? I guess that's really step one.

EDIT: Kite found the right family in her previous post, on the 1841 census in Sutton: James Berry, 50, Sizer. He is my MFFFF. In my post here, on the 1881, are my MF Walter and my MFF James (grandson and namesake of James Berry born Colne).

The families in the earlier posts, from Carr, Sowerby, Halifax and Bradford Moor, Bradford, Yorkshire, it turns out are not at all mine.