Yes, that is the correct Richard Russell. The marriage was on the 12th March 1861 so before the Census for that year, which I believe was on the 7th April.
I am not sure that the 1851 census in Dover, Kent is him as two of his older brothers are still in Hammersmith working in a bank at that time. Thomas was married in Kensington in 1854 to Valeria Harley who was a sister of Richard's bride Rosa Harley, but the age and birth place look very good.
It is intriguing to me that he managed to become Auditor General within 11 years of being perhaps a clerk. I think I need to find out what sort of position it was e.g. civil service, army etc. His son C H Russell 's entry in Oxford University matriculation lists his father as " Richard, arm." which I assume means army ? This family tree stuff can definitely be a 'two pipe problem' - where's Watson when you need him !
Census Record for the brothers :-
RG number: HO107
Piece: 1571
Folio: 386
Page: 29
Reg. District: Lambeth
Sub District: St Mary's Lambeth 1st Part
Parish: Lambeth
Enum. District: 20
Ecclesiastical District: St Mary's 1st Part
City/Municipal Borough: Lambeth
Address: 6, Wolsingham Place, Lambeth
County: Surrey
SAXTON, Charles B Head Married M 38 1813 Gacler At White & St Prison Melcombe, Dorsetshire
SAXTON, Matilda Wife Married F 45 1806 St Geo H S, Middlesex
POIDEVAN, Charles Boarder Unmarried M 27 1824 Clerk To A Banker St Jas Westr, Middlesex
POIDEVAN, Ellen Boarder Unmarried F 26 1825 Annuitant St Jas Westr, Middlesex
COSSER, Letitia Inmate Unmarried F 44 1807 Annuitant Calcutta B Subject
RUSSELL, John Inmate Unmarried M 26 1825 Clerk To A Banker Hamh, Middlesex
RUSSELL, Thomas Inmate Unmarried M 20 1831 Clerk To A Banker Hamh, Middlesex