This Guy has been responsible for a lot of the model work on Space 1999, Flash Gordon, Alien, Outland, Blakes 7 and Dr Who to name but a few. He also has built replicas for Gerry Anderson and this site has a lot of tips and info on it...check it out.
http://www.martinbowersmodelworld.com/
http://www.martinbowersmodelworld.com/