While waiting for the test boards, Frank created the big board and Gert placed the components and added some silk screen labels. Collaboration was easy with github and Slack. KiCad rendering of the top side:

The idea is to use standoffs and mount the MIDI connectors etc. on the back side of the PCB. Then on the top side an acrylic panel could be mounted. This is how the bottom side looks like:

The only SMD parts are the 3 TM1638 chips. If we sell it as a DIY kit, this would be pre-soldered, because many hobbyists still think SMD parts are difficult to solder.

The routing was done with TopoR as well: