The address in 1941 is not, alas, going to be much of a help. The main use of an address is to help find a name on the electoral register but there were no registers made between 1939 and 1945 because of the war.
My strategy would be this:
Get the marriage certificate. This should give you a slightly better idea of his age and confirm his father's name and occupation. There is also the possibility that one or more of the witnesses will provide added clues.
The father's occupation may turn out to be distinctive enough to find him in the 1911 census. If you are lucky, he will already be married and the census will then show for how many years. You should be able to identify one or more possible marriages.
Once you have some possible maiden names, you can cross check these with the possible registrations of your grandfather's birth.
I hope the above makes sense and is helpful. It is understandable that you want to avoid "unnecessary" expense, but you need to be aware that family history is not, never has been and never will be a cheap hobby. Cutting corners by bypassing certificates is a false economy as your tree will then be a matter of guesswork rather than research.