what an awesome site. Do you know of any other sites that have helmets and or guns?
There's only a bluezillion sites out there.
Just Google "papercraft." I know The Dented Helmet has/had a pattern for the Fett helmets.
www.instructables.com had a tutorial for the Fett helmet, and I think some of th Fett armor. There's the papercraft Pulse Rifle, Judge Dredd movie Lawgiver and Terminator 40 Watt Plasma Rifle. There's the papercraft Klingon Disruptor and Space:1999 Stun Gun.
http://www.zealot.com/forum/forumdisplay.php?f=7 is a really good papercraft forum, but they cover aaaalllll sorts of models, not just props.
http://users.sdccu.net/chthulhu2/models.html has Marvin the Martian's raygun and Space 1999 gun and comlock.
http://www.bazookajo.me.uk/ has the classic Cylon helmet. There are a number of others, but that's all I can find just now. I know there is/was a site that had a bunch of real world guns in papercraft, but I'm not seeing it just now.
There are also buttload of free Google Sketchup models. There is a SketchUp plugin that unfolds the models. And people have made wads and wads of models.
Here are some more links:
http://aliens.humlak.cz/aliens/aliens_papirove_modely_gb.htm - pulse rifles, lawgivers and plasma rifles..
http://uhu02.way-nifty.com/blogpapercraft_ver2/ ... I'm not sure if they're still up, but SOMEWHERE there are/were models for the Noisy Cricket, and Bladerunner Gun. I know there are a number of places that have done Iron Man models and Halo models. And several people have converted them into ful sized costumes. Someone on the Zealot has also created a low polygon classic Viper helmet. Someone else has done a Pepakura Boush and Red Guard helmet. The Red Guard used to be free, but I think he's charging a small fee for those. You should be able to find links on The Dented Helmet.