Have you read any books in the Parasol Protectorate series? It is light steampunk in a world were the acceptance of werewolves and vampires in to society is the reason for the rise of the British Empire. May be it could be an inspiration.

On the bit more dystopic line of books I can recommend 'Unnatural History' by Jonathan Green, with shows some of the shady sides of a steam-/dieselpunk London where queen Victoria is kept alive (or is she?) by cybernetics and role a British Empire that never fell