I had a look on the Dean census for 1841 and could find no SETCHELLs at all- I also looked in Keysoe as there is a link with that village too [see below]. There are no SATCHELL/SETCHELL Wills in the archives or gaol records.
Firstly, marriage of George SETCHELL & Mary FAIRY on the 28th Aug 1821. Mary signes her name/ George makes his mark +. Their witnesses were Charles DAVIES [?] and Judith SETCHELL
Some christenings/marriages/deaths take place in Dean/some in Keysoe. Here is what I have found:
1753: christening - Jonathon, son of John & Sarah [24th March/Dean]
1757: christening - Thomas, son of John & Sarah [31st Mar/Dean]
1770: burial - Sarah, wife of John [labourer, 23rd Dec/ Dean]
1771: marriage - John, labourer & Jane CLAPHAM [widow, 26th May/ Dean]
1779: burial - John [labourer, 1st Jan/Dean]
1779: marriage - Thomas marries Mary NEWHAM [5th March/Keysoe]
1780: christening - Muriah, daughter of Jonathon & Mary [27th Feb/Dean]
1781: christening - Thomas, son of Thomas & Mary [29th April/ Keysoe, father was parish clerk]
1781: burial - Thomas, son of Thomas & Mary [ 6th May/Keysoe, father was parish clerk]
1783: christening - William Newman, son of Thomas & Mary [ 26th Nov/Keysoe, father was the parish clerk]
1783: burial - William, son of Thomas and 'the late Mary' [27th Nov/Keysoe]
1783: burial - Mary, wife of Thomas [27th Nov/Keysoe]
1785: marriage - Thomas [widowed] & Martha FLANDERS [21st Feb/Keysoe]
1787: christening - Cath, daughter of Thomas & Martha [private christening performed by the Rector of Pertenhall on 15th Sept/ Keysoe]
1788: christening - Pru, daughter of Thomas & Matha [3rd Oct/ Keysoe]
1790: burial - Pru, daughter of Thomas & Martha [27th April/Keysoe, father was parish clerk]
1790: burial - cath, daughter of Thomas & Martha [ 17th July/Keysoe]
1793: christening - John, son of Thomas & Martha [16th May/ Keysoe, aged 6 months, father was parish clerk]
1793: burial - John, son of Thomas & Martha [18th Dec/Keysoe]
1794: christening - Elisha, son of Thomas & Martha [11th Jan/ Keysoe, father was parish clerk]
1798: christening - George, son of Thomas & martha [13th April/Keysoe]
1802: christening - Kitty, daughter of Thomas & Martha [aged 17th months on 29th May/ Keysoe]
1802: christening - Kitty, daughter of Thomas & Martha [30th May / Dean]
1804: christening - Judith, daughter of Thomas & Martha [22nd May/ Dean]
1807: christening - George, son of Thomas & Martha [10th Oct/ Dean]
1810: christening - John, son of Thomas & Sarah [12th June/Dean - from Bedford]
1817: marriage - Elisha & Ann CHERRY [24th Jan/Dean - Elisha signs register]
1820: burial - Martha, aged 59 [22nd April/ Upper Dean]
1821: marriage - George & Mary FAIRY [see above]
1822: burial - Mary Malvina [? aged 16 weeks, 7th March/Upper Dean]
1822: christening - George Lewis, son of George & Mary [14th April/Upper Dean - father was a labourer]
1822: christening - Rich, son of Rich & Cecilia [27th Oct/Upper Dean - father was a carpenter]
1822: christening - Oliver, son of George & Mary [20th Dec/Upper Dean - father was a labourer]
1827: christening - ? Fairy, son of George & Mary [ 27th May/Upper Dean - father was a labourer]
1831: christening - Eliza, daughter of Elisha & Ann [date? Upper Dean - father a cordwainer]
1831: burial - Elisha - [aged 37 years on 13th March 1831]
1841: burial - Thomas [aged 85 years on 6th Feb/Upper Dean. Note: he was parish clerk]
The Catherine SETCHELL aged 52 on the 1851 census is an unmarried 52 year old lace maker, possibly the 'Kitty' who was christened [twice?] in 1802?
Let me know if there is anything else I could look up?