Thanks to the fact that the GRO death index shows date of birth after 1969, it would be an extraordinary coincidence if this wasn't him:

Name: William Jennings

Birth Date: 9 Jul 1928
Date of Registration: Feb 2005
Age at Death: 76
Registration district: Hull
Register Number: A71A
District and Subdistrict: 550/1A
Entry Number: 297

Using this information, you can order the certificate (£9.25 from www.gro.gov.uk). If you are lucky, the informant will be a relative and their name and relationship will help you piece together his life between birth and death. More information might be gleaned from his will. Go to https://probatesearch.service.gov.uk/#wills to order it online (£10).

Hope this helps

Caroline