I Am Looking for Information on Peter Evelyn Graham Born 1923

Peter was born in 1923 and lived in Brighton/Hove Sussex.He died in the 1970s.
Now I know this is a big ask, but I am trying to find out what armed services he was in I'd say around 1942. Army or Navy. or even the school he went to.
He was known as Peter the painter. Already have a lot of family info but no photos , no photos of his mothers marriage either. She married James harol Graham ( an acrobat ) in London in 1913. Any help really appreciated. Thank you.