The FreeBMD has a marriage entry from the third quarter of 1900 for a George Albert Brock in Bradford, Yorkshire that has an Eva Jackson Parkinson on the same page. If that is your George and Eva, then there is a death registration in the FreeBMD for an Eva Jackson Brock, 35, whose death was registered in the fourth quarter of 1903 in Bradford, Yorkshire (volume: 9b, page: 68).
There is another marriage for a George Albert Brock in the fourth quarter of 1905 in Bradford, Yorkshire (volume 9b, page 228). The names of the women on the same page are Cecilia Hickey and Alice Rigby but there's no way to tell for certain which one married George without ordering a certificate. However in the FreeBMD there was a death in 1929 for an Alice Brock, 51, in Bradford, Yorkshire and a death for a Cecilia Skilbeck, 49 in 1930 (the other man on the page of the 1905 marriage entry was Alfred Skilbeck).
There is a family tree posted at Ancestry which shows three marriages for George:
1) Eva Jackson Parkinson
2) Alice Rigby
3) Lydia Rigby (Information from FreeBMD index, third quarter of 1930 in Belper, Derbyshire - volume 7b, page 1831)
It also has a date of death for George as 17 Aug 1935 but doesn't say where.
I think you can access trees in this section of Ancestry without a paid subscription (you might have to register though):
http://awt.ancestry.com/cgi-bin/igm.cgi?op=GET&db=shaz1&id=I19622The page indicates the tree was updated last in Apr 2008 so hopefully the email address listed with it will still be good if you wish to contact the person who posted it (her name is Sharon). If you aren't able to access the tree through the link please let me know and I'll PM Sharon's email address to you.
Jacquie