4 Millbank SW1

No 4 Millbank was built in 1912 by Simpson & Ayrton for the Crown Agents. The allegorical figures over the entrance are by Albert Hodge. London possesses few of Hodge's works - born in Islay, he began his career in Glasgow and died in 1918 at the early age of 43.
The female on the left sitting on top of an Ionic column is not as generously endowed as most Edwardian lovelies, which is typical of Hodge. Both figures have muscles like penny rolls, as Robert Louis Stevenson said, which is another characteristic of Hodge's work.
The male figure carries a bundle of fasces, so he must be associated with justice. Note the tiny winged figurehead under his left hand, implying that he is sitting on a ship. You can just see a mooring ring behind him to his right.

54 Harley Street W1

Sometimes quite ordinary houses sport just one lively and interesting detail that makes the whole thing come alive. At 54 Harley Street, a solemn neo-Georgian house built for one of the consultants that infest the street to this day, the keystone over the front door is carved with this lovely mermaid. She holds a trident in one hand and twirls her hair seductively with the other. Her tail curls round and round itself - it must be the longest mertail ever.
The house was designed by Niven and Wigglesworth in 1904, so the sculptor may be Albert Hodge or his assistant Charles Doman.