Two Percy Street addresses have connections to Orwell. Number 13 is the Elysee restaurant, specializing in Greek food. Orwell liked the moussaka here; Arthur Koestler apparently hated it. Number 18 was the flat where Sonia Brownell lived. Orwell visited her here in the late 1940s before his his last illness. She became his second wife in 1949, as he was dying. (source: Orwell's London, pg. 112)
18 Percy Street, flat of Sonia Brownell.