Thank you so much everyone who is trying to help, we have the following information which can be seen on Ancestry.com.
William Whitmore, Name used by him, No accurate source confirmation
DOB given by him on joining Military 21 May 1876 No accurate source confirmation
DOD 23 July 1918, The person who called himself William Whitmore, see above died on the date given.
Wife Margaret Bessie Cook, Full history found, age on Marriage certificate in correct.
We have full confidence in all records that we have found after 1895. It is prior to that date we need.
We believe that there was an Aunt Liz who lived in Doncaster 1907-1911 or longer but we cannot trace her from the information we have.
Search - William Whitmore 1876+/-2 years, died 25 July 1918, Anna Sophie will find about four independent family trees, his history can be found in Google, doing the same search