William E Brock may have birth date of 1866 in 1901 census, but shows on a tree on ancestry, and looks to be in other censuses as 1863/1862 Devonport.
There is a death for a William E Brock age 58 in 1921, Devonport, which could be him.
Added:
Yes, died 27 August 1921, general labourer, administration to Mary Jane Brock, widow.