Many accurate 1921 census transcriptions have already been added to the pub history site, including London, and parts of Middlesex.
Clerkenwell pub history index
This is almost certainly to be a private address, Edwin Gravatt is at the Corner Stone in 1882 or the Lion
Historical London public houses, Taverns, Inns, Beer Houses and Hotels.
Residents at this address.
1881/Edwin Henry Gravatt/Licenced Victualler/27/Newington, Middlesex/Census
1881/Elizh Hannah Gravatt/Wife/24/Pentonville, Middlesex/Census
1881/Lilian Gravatt/Daughter/4/Islington, Middlesex/Census
1881/Kate Gravatt/Daughter/3/Islington, Middlesex/Census
1881/Nelly Gravatt/Daughter/2/Islington, Middlesex/Census
1881/Minnie Gravatt/Daughter/6 months/Islington, Middlesex/Census
1881/Sarah Collier/General Servant/26/St Margarets Bristol/Census