Finally got the new case together. My woodworking skills are rudimentary at best and it shows, but it does seem to be sturdy and functional enough. Not a moment too soon, either; it’ll be full before long!
The panel in the middle is a bunch of passive “jumblers”/multiples and attenuators. The former good for both converting between 3.5mm and 1/4”, and for splitting out noncritical signals. On the right a stereo jack gets split out to two sets of mono jacks.
Building this has been occupying me for too long, but now it’s back to electronics!