Thanks for all the replies, but I'm more confused now !
lzdb:
I can only find one possible in 1851 viz. HO107 2117 30 18, living with Uncle Joseph King. Can you please give me the other possibles.
Geoff-E:
That is a coincidence as I came across a baptism for William Thompson Selby, 5 Jul 1843, mother Martha -will look back as I seem to have lost that link, maybe FamilySearch so
!
Overall I think the advice of the Marriage Certificate is the next step, to establish both the father's name (hopefully) and his status (s or wid.)
Thanks again for the help,
Mike W