I also have (thanks to the Sharp guy) the complete pinout specs of the input connector.
The upshot of all of this is that, in about a week, I'll have all the resources I need to start working on powering up this panel. Once I've pulled that off, it should be almost trivial to actually hook up the composite inputs, and I'm in business.
I figure on cannibalizing a couple of the ribbon cables and using them to hook up dummy leads to different pins on the input connector. That should let me experiment with just powering it with no signal, and all that good stuff. It will probably be a fairly delicate and messy process until I learn enough about the panel to build a nice compact circuit - but heck, that's half the fun of it.
I got talking to the Spectral Samurai about all of this, and we've agreed that the coolest thing to do is figure out how to take advantage of the analog RGB support that the panel has, and building an actual computer from scratch with it. Once the video signal bit is taken care of, it should just be a matter of putting together a microcontroller and ROM that can be used as the video interface. Another microcontroller, some more programmable ROMs, and a little bit of wizardry, and I think we can actually build a fully functioning architecture here. Building up a complete system and coding an OS on bare metal will be a hell of a challenge, but you just can't get much more cool than that.