This is an alternate design for a Tiptop Audio Happy Ending rack kit that will sit atop a Behringer 2600 in a 19" rack frame (See my Happy Ending Rack Master). The idea here is to work with more modulation sources and build around having two Korg SQ-1 Sequencers on the desktop. I've included a switch in the plan to work with those two.

A video of my tiny playground here: