I have been to Nottingham where the Sutton Bonnington parish records are held, and I cannot fine a Joseph bprn to William and Mary abt. the date you ask.I have found 2 William and Mary marriages and neither had a child called Joseph.One was only maried in the early 1850/s but no son called Joseph and the other was my ancestor.s first wife who died in 1837 and only had a daughter.There was a Joseph bborn in Loughborough which is abt. 50 miles away and where a lot of the Dalbys originated from born in the mid 1850,s according to the official register og Births, but even on that register I could nor find a Joseph born abt. then.. Could your father have a mix up on the dates? or the parents?