Hope I'm not overloading your "inbox".
I am now beginning to thing Barnet wasn't sure what his age was when he completed his census records (some of mine didn't seem to know either). I am now beginning to think that he was in fact born in 1842 - I found a birth registration in that name.
It is probably still worth trying to trace it down from the previous Barnet Fullard. I will have a go.