That spacious desk surface is attached to the rear edge of the enclosure with a piano hinge, providing easy access to all those aforementioned guts anytime the need arises. And while the photo below doesn't really show it, there's even a decent amount of storage space down there in front of the battery.
The keyboard began life as a garden variety M-Audio MIDI controller, which I boldly disassembled mere hours after it arrived. Why? Because in its out-of-the-box state, the keyboard was about an inch too wide to fit in between the cabinets on either side of the van. Sure, I could've taken the easy way out and bought a four-octave keyboard, but I really wanted five, so a bit of hacking was required.
I separated all the components that I wanted to use – the raw keyboard mechanism, circuit boards for the volume slider and octave up/down buttons, along with the various ports on the back – and tossed the rest. Something tells me warranty service is off the table now, but such is the price of being a maverick. Anyway, the raw keyboard was plenty narrow enough to fit in the space I had to work with, so I just had to figure out what to do with the other pieces of the puzzle.
The above photo shows the guts mounted on the underside of the keyboard shelf, all wired up and working great, but I still needed some sort of protective cover for everything. Enter Q, who has recently been severely bitten by the 3D printing bug. With plastic now on the growing list of materials he can fabricate with, I sketched a rough design of the two boxes I needed, and just a day later he laid these two babies on me:
Not much to look at, but they're not really going to be visible anyway. What's important is that the circuit boards are now well protected, and if you look closely, you can see that all of the controls and ports are within easy reach.
There's still a little bit of work to do on the desk, but it's a relief to have worked out all the big problems that it posed. All downhill from here as a result, and believe it or not, I predict that I'm now just a couple of short weeks away from wrapping up this colossal beast of a project.