So after a year and a half of driving with no radio, I finally broke down and installed one.
The major hang up was the huge mess someone made of the factory harness. Lets just say it was ruined. Between yesterday and today, a friend and I worked it all out.
The only thing I had to deal with was some speaker wires (the ones in the door were very well hidden; the rear wires were totally intact), and a mess of a harness up front. Using a multimeter I managed to work out what wires were for what speakers, and got my speaker harness together (this was faster and less painstaking than running new wires). From there it was just a few power wires, and I was set. I got some (pardon my car audio illiteracy) radio from Sony and a matching set of speakers. My friend bought them for me because I am entirely useless on the subject of car audio.
I did not move my gauge cluster in the radio housing, so I had to mount the radio in the glovebox, which is a fabulous location for it. It is very slick and well hidden, which is important seeing as I have inoperable door locks on the front doors. I have yet to make the final mounting bracket for the glovebox. Maybe some pics when that happens.
Overall, a fun project that was really easy. The longest part was mounting the speakers so that they looked almost factory. Mission accomplished.