This used to be "mystery bust" in Puzzle Corner but our colleague, Alan Patient, has done some research into the appropriately squiffy-looking portrait and found this building to be the dead pub, the Earl Russell. The title was created in 1861 for Lord John Russell who totalled about 7 years as Prime Minister and died in 1878. Puzzle solved - we'll buy Alan a pint in the Earl Russell should it ever re-open.
Site: Earl Russell bust (1 memorial)
W1, Mortimer Street, 22, Earl Russell