Many accurate 1921 census transcriptions have already been added to the pub history site, including London, and parts of Middlesex.
Clapham pub history index
Historical London public houses, Taverns, Inns, Beer Houses and Hotels.
Residents at this address.
1911/Enos Green/Stone Dresser/36/St Albans, Hertfordshire/Census
1911/Mary Eliza Green/Wife, Assistant in Beer HOuse/32/Erbistock,
Wales/Census
1914/Frederick Speedy/Beer Retailer/../../../Post Office Directory
1919/Frederick Speedy/Beer Retailer/../../../Post Office Directory
1921/Frederick Speedy/Beer Retailer/../../../Post Office Directory
1934/Leonard Marshall/Beer Retailer/../../../Post Office Directory