I picked this up recently and treated it to a new power supply board for the PS/2 board stack, so I figured it needs better lighting now. It's a slightly different twist than typical passenger cars, at least for the head unit, there no room for the standard LED strip! However, I have on hand a couple of the really narrow LED strips, purchased for just this kind of job. It's a tight fit for sticking the LED regulator board in as well, but I replace the AA batteries with a supercap, so the LED regulator board fit into the battery holder with the supercap.
I repurposed some of the existing lighting metal for the job and added connectors all around so you can disassemble the unit without a soldering iron.