Is this Seth (as James) in 1881?
Dwelling: 4 Bedford Place
Census Place: Cardiff St John, Glamorgan, Wales
Source: FHL Film 1342269 PRO Ref RG11 Piece 5276 Folio 56 Page 15
Marr Age Sex Birthplace
James DENNING M 35 M Oakhill, Somerset, England
Rel: Head
Occ: Driver
Mary Ann DENNING M 36 F Bath, Somerset, England
Rel: Wife
William DENNING 14 M Bath, Somerset, England
Rel: Son
Ida DENNING 10 F Bath, Somerset, England
Rel: Daur
Lily DENNING 7 F Bath, Somerset, England
Rel: Daur
Ernest DENNING 5 M Bath, Somerset, England
Rel: Son
Albert DENNING 3 M Cardiff, Glamorgan, Wales
Rel: Son
If it is then they may have moved to Glamorgan between 1876 - 1878 (due to the children's birthplaces).
It may be an option to post a look up for the Seth James Denning in Bath England for 1851 - 61
I also found a Birth entry for a Seth Denning in the Free BMD's, which ties in with the 1881 Census information:
Births Jun 1846
Denning Seth Shepton Mallet 10 465
Seth May have had a brother also named William
Births Jun 1845
DENNING William Shepton Mallet 10 441
