yeah thats how it works, you send them something with a filled out return envelope and if they're nice enough (which generally they are) you get it back signed.
i don't know of any addresses but im sure there are a few people on here who do. but you could try sending it to their club that usually works.
im sure someone else on here would be able to give you more info though, im more NRL / Soccer Based as opposed to cricket i just thought i'd let you know what TTM meant