This is my box insert for Tiny Epic Zombies that I designed in SketchUp, I have Included the source SketchUp files in case you want to make tweaks. It is unlikely going to fit big cards with sleeves, the smaller cards could probably be sleeved.

If the holes in the armory part are too big adding some blue tack putty into the holes works great! Thank you @evilariena for the suggestion.