K,
This business of considering candidates , eliminating the "wrong" ones and hopefully "inking-in" the "right" ones, is normal for us all.
I assume you worked your way backwards from present-day back to your target William Blakey, who you knew from corroborative evidence that he was born in Berwick upon Tweed circa 1803.
So you target his baptism and consider a candidate baptism in Newcastle., but rightly question the distance separating Berwick and Newcastle.
But we discover two similar William Blakeys in Northumberland censuses, one born Newcastle living in Newcastle, , the other born Berwick-u-T living in North Shields.
Then Jennifer finds a William Blakey birth/baptism, in Berwick upon Tweed, son of William Blakey and Mary Riley,
As there only seems to be two candidates from censuses for William Blakey, one born /baptised Newcastle and the other born/baptised Berwick... and your target was Berwick-born.. then Bob's your Uncle !
Michael