Isle of Trains card game inlay

Isle of Trains is a card game that comes in a box that's a little too big for the cards. It's not really a problem but I wanted a simple 'problem' to solve and this fitted the bill perfectly.

There are no finger slots as I thought it looked better without them, plus it's easy enough to flip the box over. Also, I messed up in Tinkercad with the hole: I didn't lower it through the plane, so there's an internal lip at the bottom of the card slot. I was going to fix it but I kinda like it, especi