It's an enormous leap of faith to even consider that William (and Sarah) in Thornbury Gloucs is the same William in Hunts, 150 miles away.
If William married Alice in Gt Gidding, she was buried in Gt Gidding in 1820, he died in 1845 in Oundle RD which includes Gt Gidding, and he was buried in Gt Gidding, I think there's every chance he was in, or close to, Gt Gidding in the intervening years. It would be pretty unlikely for him to move to Gloucestershire and then move back to Gt Gidding again. As I said, there were no William Hughes - Sarah marriages in Hunts 1820-37
The 72 year old tailor in Thornbury Gloucs in 1841 appears to have been buried in Thornbury on 14 Dec 1843 age 77 - both 1841 and burial ages are notoriously suspect - but I think you can rule him out. If the marriage isn't on the IGI at
www.familysearch.org it will be difficult to trace them. A Sarah Hughes 76 widow born Bath Somerset was still living in Thornbury in 1851, mother in law of William Bailey 46 and his wife Jane 37 (presumably Sarah's daughter)- according to FreeBMD William Bailey and Jane Hughes appear on the same page in the Sept 1839 marriage index at Bristol registration district. Forget Thornbury!
But...
Polebrook Northants is 4 miles from Gt Gidding. In Polebrook in 1841 there's a William Hughes 70 independent, born in Northants. 70 in 1841 covered an age range of 70-74. Oundle registration district also included Polebrook. Might be worth researching further - starting with his death cert to see where he died. But there was also another William Hughs who died the previous year in Oundle RD
David
