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.
A listing of the Taverns, Hotels, Inns and Coffee House in 1822-23
You cannot link to all pages from the index, it points the start page for a letter, then use next - or alternatively just use the search engine to search for your ancestors!