I think his death was in 1928?
From GRO Deaths:
SUMNER, JAMES THOMAS 72
1926 D Quarter in ELHAM Volume 02A Page 1379
SUMNER, JAMES TUCKER 64
1928 S Quarter in BRENTFORD Volume 03A Page 99
Westminster Burials
Hanwell Cemetery Middlesex
12th Sept 1928
James Tucker SUMNER 152, Framfield Road, Hanwell
age 64 Grave No 9801
London Electoral Register
Year 1928
152 Framfield Road, HanwellJames Cuthbert Sumner
James Tucker SumnerRuby Sumner
Edit to add
James Cuthbert Sumner Age 26 Sawyer father James Auditor
married 25th December 1914 at St John the Baptist Church , Great Marlborough Street
Ruby Leah Chapman age 25 father William, jeweller