I think I have found your William Ollerhead as a child, & he obviously followed his father's footsteps.
From the 1841 Census for Wrexham Town
The family were living in Hope Street, Wrexham.
John Ollerhead, 45, Confectioner, (born of this parish)- no
Elizabeth "" "", 40, yes
Margaret "" "", 15, yes
Caroline "" "", 15, yes
John "" "", 11, yes
James "" "", 10, yes
Elizabeth "" "", 8, yes
William "" "", 7, yes
Richard "" "", 5, yes
Herbert "" "", 4, yes
Mary "" "", 3, yes
I trust this helps...