Jeep CJ7 Dash Box

I have a 1981 Jeep CJ7 that a PO put a radio into. In order to do that he cut a hole in the original dash so that a modern radio would fit. I took it out when I got it because the radio didn't work anyway. That left me with a nice square hole in my dashboard though. They sell aftermarket radio hole covers for CJ7's but since my dash was cut none of those would fit. I decided that rather than have a hole in my dash I would design and print a box to fit into the hole so I can at least get a t