If you can manage with plastic an AMTronic can be picked up for as little as $11 on eBay. It shouldn't be too hard to strap on a pair of outrigger thumb drives and you'll have it.
I am waiting still for a reply from the fella with the computer model. If he forwards it, i'll share it with a designer , like I was asked.
As for the shuttle above; nice work, though to me it looks like a sleek, Fed Agrav of the TOS period, until you see the interior. I could easily picture have this on the show.
Making it into something that could be made out of paper would mean many compromises. I think the bottom could be made out of once piece, with a little deviation, but the top would have to be broken up, not too much though.