Yes, the Elizabeth Candwell in the 1851 census is William's wife. I didn't have the information that she was 69 years old. The census was taken on 30th March 1851, which means that she was born between 31st March 1781 and 30th March 1782. We can narrow this down from the previous information to say that she was born between 31st March 1781 and 7 June 1781.
Ann Lucas was Elizabeth's daughter. She married Thomas Lucas on 7 Feb 1824 at Egmanton. John Caudwell, her brother and my ancestor, was a witness at the wedding. Ann was baptised 20 Jan 1805 at Egmanton.
The Elizabeth Caudwell in the 1841 census is William's wife, which means that William had either left home, died or was living in an institution. His daughter Charlotte's marriage certificate (to Richard Saxby) on 8 Feb 1838 shows William as a Carpenter. It does not say that he was deceased, but apparently that was not always shown on certificates. So, he may,or may not, have been alive then.
There are many records of deaths of William Caudwells around that time. Is the one you are referring to Southwell, vol15, page402 ? I have a copy of that one, which is for William Caudwell who died on 8 Sep 1843 aged 14 years. He is not our William.
There was another William who died 29 Jan 1859 (Southwell 7b 256) but he was only 4 years old. I've checked quite a number of these out and found nothing of our William. It's been very frustrating over several years.
There is an outside possiblity that William Caudwell baptised 29 Nov 1748 at Egmanton is our William, but he would have been about 50 years old when he married Elizabeth. Seems unlikely.
Barbara Caudwell (1744) did have 2 illegitimate children, one born in Lincolnshire. I intend to scour the Lincolnshire records sometime soon to see if William was born there.
The project drags on, I'm afraid.