Neat idea - unfortunately there's no way my wifey would let such a thing fly. It's hard enough for me to sneak a new knife or pistol in without being caught haha!
I would probably draw out the design of the display the way I envision it, and then build it from there. I like newdebate's idea of dart board material. Corkboard would do well. You could use small pins, similar to those used in biology labs for taking their animals apart. The background could be applied with a solid sheet of cloth or whatever material you choose, so long as it's something the pins can penetrate through. Maybe even an MT sticker or logo included in the background? Please post some pics when you figure it out. Can't wait to see it!