Will do this in stages. I only have a few for 1861 -
No Blackmores in 237/238/239 which is Shoreditch
None in 213 Cripplegate
None in 332/333/334 which is Southwark.
Just rechecked the latest index and there is only the one showing that I gave you before.
Sorry but at least you know where they weren't.
S & N have the census set - as follows
http://www.genealogysupplies.com/index800.htmLondon 1861 Census
£ 49.95
Supplied as Acrobat documents with Street and Area Indexes. Coverage includes: Kensington - Chelsea - St George Hanover Square - Westminster - St Martin in the Fields - St James Westminster - Marylbone - Hampstead - Pancras - Islington - Hackney - St Giles - Strand - Holborn - Clerkenwell - St Luke - East London - West London - London City - Shoreditch - Bethnal Green - Whitechapel - St George in the East - Stepney - Mile End Old Town - Poplar - St Saviour Southwark - St Olave Southwark - Bermondsey - St George Southwark - Newington - Lambeth - Wandworth - Camberwell - Rotherhithe - Greenwich - Lewisham
They also have one for Middlesex but think the London one would probably cover where you are looking.
It appears from what I have seen on r/c - that no one actually has the 1861 - or if they do, not doing lookups from it.
Cougar