Electoral registers showed John Thomas Tavener with Ellen until 1929. It would seem he died 1943.
I believe he set up home with Edith** and they appear together in 1939(dob as 4.9.1875)as just John & Edith.
They appear at the 1939 address in 1937 @ 103 New Cavendish Street as John Thomas Tavener and Edith
1936 they appear as John Thomas & Edith @ 43 Upper Marylebone Street
1932 John Thomas Tavener & Edith @ 101 Euston Street, St Pancras
1930 John Thomas Tavener & Edith @ 8, Wellington Street, St Pancras.
SS