Many accurate 1921 census transcriptions have already been added to the pub history site, including London, and parts of Middlesex. If you can contribute to the site, send me some details to Kevan, along with some description of the specific property.
This is a listing from the Public Houses section of the UK London Post Office suburban Directory in 1911; it lists an alphabetical listing of these Public Houses in London, the Publicans and also has links to the relevant Public House page listing of the Licensees, Bar persons and Boarders and Lodgers etc. All information on these pages comes from London census, Post Office and Kelly Directory, plus any information and pictures supplied by You.
Public Houses in 1911