That was my plan, putting the sheet rock on the inside.
Here are some more pictures. I haven't accomplished too much more. Past few days have basically been thinking days.
I have tacked on the hinges just to get an idea. Two of the pictures shows the hinges (door opened and closed) and then the other two pictures show the pins that lock and unlock the safe. The whole locking system is not complete yet... Making minor adjustments as I go.