Ok the main box is complete. Nice tight fit around the connector. Everything is so carefully dialed in that I can probably remove the recessed screw holes entirely because it’s a very nice friction fit. I also increased the thickness of the base so that it sits flat on the shelf behind the Marty without putting any downward strain on the connector (though I accidentally made the extension a fraction smaller but that visible line has already been fixed). The top is almost done, but creating the slide switch to integrate with the top will be tricky.