That's quite a nifty little box you've made there.
I'm thinking of mounting my reversing camera monitor in that position (being a commercial & on business policy, the insurance company prefer both reversing alarm & either audio or visual warning other than mirrors), also got a couple of switch boxes, which I'll try to see which fits in the cubby hole above the CB, if neither fit, then I'll have to have another look, although I don't want to have to order another switch box