In the 1841 census
Ambrose Paradice
aged 76 - born c1765 not in county
St James Out and St Paul Out, reg dist Clifton, Gloucestershire
independent means
others in household:
Elizth Cook, 86
Martha Paradice 22, born in county
Ann Paradice 25, not born in county
Charles Osborne, independent means
Ann Triscott, 14, servant
Ambrose's name was corrected in 2012 by a user at Ancestry. Is that a person you are in touch with?
If he was actually 83 in 1843, his year of birth would have been rounded up in 1841 to 1761, not 1765 - giving age 76 rather than the rounded 75 makes it look like he was being accurate.
So the 1765 birth / 1769 baptism for that Ambrose seems quite plausible.
https://familysearch.org/pal:/MM9.1.1/NFRZ-S1Mbaptism of Martha Paradice, daughter of Ambrose and Elizabeth, Nov 1814, Bristol.
That would have made her 26 in the 1841; given the odd order of the names by age, I wonder whether they got switched?
There is also daughter Elizabeth born 1812 Bristol (died 1813), and there are births to an Ambrose and Elizabeth couple in Corsham, Wiltshire:
John 1797 (mother Betty), Ambrose 1800 (mother Betty), Elizabeth 1802, Ann 1804, William Perry 1806, Francis 1807.
Wife was likely Betty Toors, married 1793 Corsham:
https://familysearch.org/pal:/MM9.1.1/NK3P-LGHOf the Corsham-born children, possibly:
in 1841, Francis Paradice c1811, not born in county, is in Bedminster (mistranscribed Frances at Ancestry); his son Ambrose 1839 was baptised in Bristol:
https://familysearch.org/pal:/MM9.1.1/XTQV-YQJ... Ah, here we are: in 1851 they are Parradice at Ancestry, Elizabeth born Bristol, widow of Francis, all children shown as born in Bristol.
in 1851, John Paradice c1803(?), born in Corsham, is in Bedminster.
(He was a good bit younger than his wife so might well have added to his age.)
These do support a move from Corsham to Bristol for Ambrose 1765 and family, and seem to provide the link you need to show that the Ambrose from Corsham was the Ambrose who died in Bristol.
This could be the death of Ambrose 1765's wife in Bristol:
https://familysearch.org/pal:/MM9.1.1/XTQN-ZL3Elizabeth Paradice, buried Jan 1834, aged 60 (c1774), Bristol St Mary Redcliffe.
(This would have made her 19 at the 1793 marriage, or older if the age 60 was rounded down -- but young age at marriage would mean that Ann and Martha in the 1841 could be her children, despite the fact that by 1820, Ambrose was 55 years old.)
edit - what you were actually after was the Avebury-Corsham connection rather than the Corsham-Bristol connection ... but the 1841 age of the Ambrose in Bristol may help in any event.