Thanks for the PM Holmemoss.
Whilst the dad's name is not THAT common,nothing is jumping out at me in the right area,not births deaths or marriages.
Maybe a 1948 marriage in Westminster,whish is on Freebmd? But I'm not totally convinced

Do you have an address or just a name?
Has your neighbour ever applied for his own adoption papers.
If his mum mentioned the fathers name to the adoption agency there may be more about him.
My cousin found out all about her natural dad on her papers,he was Irish though and had gone back there with such a common surname you wouldn't believe

Carol