Many accurate 1921 census transcriptions have already been added to the pub history site, including London, and parts of Middlesex.
Clerkenwell pub history index
Historical London public houses, Taverns, Inns, Beer Houses and Hotels.
The following entries are in this format:
Residents at this address.
1910/William Vernon/Beer Retailer/../../Post Office Directory
1914/Arthur Albert Barnes/Beer Retailer/../../Post Office Directory
1934/Mrs Hannah Marshall/Beer Retailer/../../Post Office Directory
1944/Mrs Esther Charlotte Figg/Beer Retailer/../../Post Office Directory