Again in 1841 there are two candidate families for George H, who was born in 1822 and was the father of George Henry Denne born in 1857.  The first:

Name Sex Age Birth Year Occupation Where Born

DENNE, William M 50 1791 Kent
DENNE, Mary     F 45 1796 Kent
DENNE, George M 19 1822 Kent
DENNE, Sarah     F 10 1831 Kent
DENNE, Emma   F 9 1832 Kent
BAKER, Elizabeth F 70 1771 Kent
KEMBER, James   M 20 1821 Kent
HAMMOND, James M 20 1821 Kent
LAMMING, Henry M 15 1826 Kent
BURTON, George M 15 1826 Kent
DIXON, Charlotte F 15 1826 Kent
CURLING, Elizabeth F 15 1826 Kent

RG number: HO107 Piece: 470 Book/Folio: 17/6 Page: 4    

Registration District: Eastry Sub District: Deal EnumerationDistrict: Ecclesiastical Parish:

Civil Parish: St Mary Walmer Municipal Borough: Sandwich
Address: High Street, St Mary Walmer, Sandwich County: Kent
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The second 1841 census for George (but as he is on his own, this is fairly useless!):

Name Sex Age Birth Year Occupation Where Born

DIXON, William   M 45 1796 Kent
DIXON, Edward         M 21 1820 Kent
DIXON, Elizabeth F 17 1824 Kent
DIXON, Mary     F 13 1828 Kent
DIXON, Louisa   F 11 1830 Kent
SMITH, Lucy       F 55 1786 Kent
FAIRBRASS, Mary F 20 1821 Kent
FOORD, Richard M 25 1816 Kent
COLTHAM, Edward M 20 1821 Kent
TOMLIN, William M 23 1818 Kent
DENNE, George M 20 1821 Kent

RG number: HO107 Piece: 486 Book/Folio: 12/24 Page: 13    

Registration District: Canterbury Sub District: Canterbury EnumerationDistrict:
Ecclesiastical Parish:

Civil Parish: St Mary Bredin Municipal Borough: Canterbury
Address: Murton Farm, St Mary Bredin, Canterbury
County: Kent
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I think the best option would be to get hold of the birth and marriage register entries for George H Denne the father.  But my strong bet is that the first census is the right man as that George was living in Walmer with his parents which is where he said he was born in the 1861 census.  If this is right, and it seems so, then we get back to the same grand-parents for George Henry that I originally surmised: William and Mary Denne of Walmer.  Finally we can conclude, tentatively, that the two Georges born in 1856 and 1857 were first cousins.

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One of the Mary Anns could be his wife:

Surname First name(s) District Vol Page
Marriages Jun 1841   (>99%)
CASSE Richard Fleet Medway 5 433   
DENNE William Medway 5 433   
FORD Louisa Medway 5 433   
GOODHEW Elizabeth Luck Medway 5 433   
JOHNSTONE Mary Ann Medway 5 433   
TUFF Mary Ann Medway 5 433   
WATKINS Henry William Medway 5 433   
WEBB Edward Medway 5 433

The Medway district includes Rochester where his wife was born.
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This 1841 household might be his:

Name Sex Age Birth Year Occupation Where Born

DENNE, William M 20 1821 Kent
DENNE, Mary F 20 1821 Kent

RG number: HO107 Piece: 470 Book/Folio: 17/6 Page: 4    

Registration District: Eastry Sub District: Deal EnumerationDistrict:
Ecclesiastical Parish:

Civil Parish: St Mary Walmer Municipal Borough: Sandwich
Address: High Street, St Mary Walmer, Sandwich
County: Kent
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And next door, as in 1861, there was a senior William, very likely his father:

Name Sex Age Birth Year Occupation Where Born

DENNE, William M 50 1791 Kent
DENNE, Mary F 45 1796 Kent
DENNE, George M 19 1822 Kent
DENNE, Sarah F 10 1831 Kent
DENNE, Emma F 9 1832 Kent
BAKER, Elizabeth F 70 1771 Kent
KEMBER, James M 20 1821 Kent
HAMMOND, James M 20 1821 Kent
LAMMING, Henry M 15 1826 Kent
BURTON, George M 15 1826 Kent
DIXON, Charlotte F 15 1826 Kent
CURLING, Elizabeth F 15 1826 Kent

RG number: HO107 Piece: 470 Book/Folio: 17/6 Page: 4    

Registration District: Eastry Sub District: Deal EnumerationDistrict: Ecclesiastical Parish:

Civil Parish: St Mary Walmer Municipal Borough: Sandwich
Address: High Street, St Mary Walmer, Sandwich
County: Kent
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Sue Jones has found a Marriage Record for St Mary’s Dover for 25 Feb 1851, by Licence, between George Henry Denne, builder of Walmer, and Mary Ann Johnson of King Street Dover, dau. of James Johnson.  Looks spot on.  (But how confusing that both he and his brother William married Mary Anns!)
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She also found these births in the Deal parish register:

Sue Jones has found a Marriage Record for St Mary’s Dover for 25 Feb 1851, by Licence, between George Henry Denne, builder of Walmer, and Mary Ann Johnson of King Street Dover, dau. of James Johnson.  Looks spot on.  (But how confusing that both he and his brother William married Mary Anns!)

This led to finding this on FreeBMD:

Surname First name(s) District Vol Page
Marriages Mar 1851
Denne George Henry Dover 5 157   
Johnson Mary Ann Dover 5 157   
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