There are a large number of Winfield's buried in the General Cemetery.
Have you tried looking there? I can't see Walter (he's the only one I looked for.)
Churchyards would be another possibility.
Many of the Indexes we have do not go to the 1950's. Bereavement Services at City Road might be able to help. They look after All the Council owned cemeteries.
Just checking as mis read the second name down you put Whitfield is that who you meant because there is a Mary Ann Whitfield buried in 1910 or was it a typo and should have been winfield.