I got the idea for this last night, when I was looking at my 32X-CD copy of Supreme Warrior. That game doesn't come in a standard Sega CD jewel case, but instead comes in a cardboard case, that is shaped the same as the plastic cases. The actual cover looks to be nothing more than a big sticker placed over cardboard cut to Sega CD lengths.
Yesterday, I bought some cardboard and made a box to the same dimensions as my Sega CD boxes. It's still bare cardboard, but sitting on the shelf it looks like a brown Sega CD box. I made it a clamshell design, just like the Supreme Warrior box, and monday I'm going to get some prints done on adhesive paper. I'm printing in 3 pieces, since I can only get adhesive prints done on 8x11 paper - the front and back pieces are entire sheets themselves, and I've made a spine piece that will wrap a bit around onto the front.
Pics of the work in progress:
I know a lot of people use DVD cases for their custom Sega CD and Saturn covers, but they're really shaped a lot differently. Anybody else ever done anything like this?