juxton,
Just so you know, alot of people on this site are slow and don't seem to read every word people write. For all of you who have replied to this already…... But as far as material goes….don't use cardboard….it's too weak. I am also using norman's plans and I'm using 1/4 in thick plywood. It's cheat and strong. Not only that, but in the movies, they used two different kinds of material…rubber for the stunt packs and plywood for the rest of them. So if you're going to go authentic, use wood. And if you're worried about it looking fake, one of the recomendations I saw before was to spray paint the whole thing silver first….then spray it black. I may just leave it at that, but, from there, you can sand some of the corners so the silver shows through, and that will make it appear as if it's made of metal. But if you make some mistakes, it's OK, the big part of your project, the most important part, is the little details. Such as the sticker and the LED and the rainbow ribon and all the expensive stuff you have to add. If you screw that up, then you pack can look bad. So don't be too anal about the boxes.
good luck,
D V D