A cousin of mine actually rented a flat at 13 Hercules, Lambeth, about 20 years. They were doing some home decoration, pulled back some ancient layers of wallpaper and found a layer with huge, hand-drawn Blake-like artwork in one patch. At the time they didn’t know the Blake had lived there, and although I have no idea what happened to the walls since then, they didn’t disturb or paint over the art. Who knows, might still be there, waiting to be discovered! The very unimpressive building is still standing and is a short walk from the London Eye.