cravend,
I searched for John's birth registration in Newcastle c.1850 +-2 yrs,( on FreeBMD) to reduce the search window when trawling through the baptisms of St Andrew's RC church.
But I could not see a candidate for him. Do you have details of his birth registration ?
If you are targeting a RC church because you haven't found his baptism in churches of other denominations, have you excluded St Mary's RC church
( now the RC Cathedral) in Newcastle, from your search, for a specific reason ?
What churches have you already covered in your search for his baptism ?
Michael