Spray paint can be your friend, or it can be your enemy.
I (finally) got around to trying to spray paint the stereo-ish computer last night, and, as you might expect, it was a disaster. I sprayed the paint outside, then tucked it into the garage to dry, and when I came back to put a second coat on I discovered that not only had the paint dripped (on the one vertical surface; the front of the case) but a whole bunch of dust had gotten into it before it dried.
Sigh.
Today's plan to finish the case is to strip all of the paint off, then either simply varish the bare metal or try again to spray-paint the thing.
If I had a better workshop, I'd give up and simply build a new aluminum case, but I don't, so I won't. sigh again.
UPDATE: I stopped at the hardware store, bought a paint stripping wheel for my electric drill, and stripped all the paint off. The bare steel case looks really good, so I've just applied a coat of clear varnish to it and. hopefully, I'll be able to oil the walnut end pieces and varnish the case tomorrow afternoon.