From the 1851 census it would appear the move to Surrey for the family took place between 1831 and 1837 and that the couple were likely to have been married in Gloucestershire - Pallots coverage is better the nearer you come towards London.
HO107 1567 folio 744
2 Camden Street Newington Surrey
Obieledom Brown 53 Gloucestershire, Head Married Door maker
Hannah Brown 45 Gloucestershire, Wife Married
Esther Brown 20 Gloucestershire, Daughter Bracemaker
Qudamah??
(the 1861 census Twindaniah) 14 Lambeth, Surrey, Daughter
Obeledom Brown 12 Lambeth, Surrey, Son
The only Edward Brown I can find born Horsley - 1851 census born circa 1839, 1861 census born circa 1838, 1871 census born circa 1839, 1881 census born circa 1835 (so could be late enough to have had his birth registered), alternates on censuses between a birthplace in Horsley and a birthplace in Minchinhampton. He was with his grandmother on the 1851 census.
HO107 1966 folio 59
Minchinhampton Gloucestershire
Elizabeth Kirby 64 Minchinhampton, Gloucestershire, Head Married Formerly a wool picker
Edward Brown 12 Horsley, Gloucestershire, Grandson Sawyer
Joseph Hill 24 Cambridgeshire, Gloucestershire, Lodger Sawyer
On the 1861 census Elizabeth was still in Minchinhampton but with her husband Walter born Minchinhampton and aged 81 a Chelsea pensioner and their granddaughter Anne Kirby aged 13 and born St. Lukes Middlesex.
I can't find Walter on the 1851 census but The National Archives have his attestation papers
WO 97/1101/251 WALTER KIRBY Born MINCHINHAMPTON, Gloucestershire Served in 40th Foot Regiment; Gloucestershire Militia; Tower Hamlets Militia Discharged aged 40 Covering date gives year of discharge. 1816
Gloucestershire Family History Society have a marriage index which you could request a search of for Obediedom's marriage.
http://mysite.wanadoo-members.co.uk/gfhs/search.htmDo you know Edward's father's name and occupation from his marriage certificate?
Regards
Valda
