Hi
I can only find this marriage that matches, so perhaps Joseph was his real name but he preferred William? So that's something you need to know to get much further. It might be worth getting the marriage certificate from the General Register Office
https://www.gro.gov.uk/gro/content/certificates/menu.asp (not really needed as I found the parish register)
Blagden Joseph Edwards Richmond S. 2a 1831
EDWARDS Doris E M Blagden Richmond S. 2a 1831
I found a parish marriage record on Ancestry.
They married in North Sheen, Surrey on 12 July 1931
Joseph Blagden 24 Bachelor, Motor Driver, his father was William Blagden a brushmaker
Doris Ethel May Edwards 24 spinster, her father was Walter Edwards a labourer
Witbesses were Frederick Joseph Alexander and Florence Hilda Alexander (it's always worth noting witnesses as they could be related)
Joseph and Doris were living at 15 Dancer Road, Richmond (useful for checking other records)
So that makes him born about 1907