The Saint in London — Leslie Charteris

Three more buccaneering adventures: When Rayt Marius bequeaths a book to Simon, it lands him in a whole lot of trouble, but it could generate a lot of money if he can survive to tell the tale. Then Simon battles the police, a reclusive millionaire, and a wild beast, and, in the final adventure, he gets rather annoyed to discover someone is stealing his identity and committing crimes in his name…