I found the death record for William in the England Civil Registration Index.
Year: 1875 Quarter: September
Record Type: Deaths Volume: 6b
District: Stoke upon Trent Page: 136
On the Family Search International Genealogy Index, there are 2 birth records:
William Hazlehurst b Apr 6 1828 Fulford, Stafford, Eng
Parents: Samuel and Prudence
William Johnson Hasselhurst b. Nov 11, 1827 Hanley, Stafford, Eng
Parents: George and Eliza
I have noticed that there are 4 or 5 spelling variations of Hazlehurst.
Fulford was in the registration district of Stone, the same district where he and Sarah were married. Hanley is in the Stoke on Trent registration district as is Longton where Sarah was born.
I'm sorry I couldn't find more specific information. I am having the same trouble getting records for my gg grandmother, Jane Hazlehurst. She was born Stoke on Trent probably in the early to mid 1820's. She could even be a sister of William. If I ever make the connection, I'll let you know.