The original radios typically all have electrolytic capacitors that have dried out. Finding someone else's "same vintage" radio won't help you. You can replace all the microminiature caps (mouser sells them) and it should restore the radio operation but it is very labor intensive. I went down this path and was able to restore the radio and tape player (replaced the belts and lubed the mechanism) to get back to normal functionality. I never could get the CD transport to work again though. It would play a little, then stall. I tried aligning it with the available adjustments but it was hopeless. I think the transport just plain wore out and there are no replacement transports available anymore.
Best bet is to install a newer Toyota radio. Stuff from the Tundra (up to 2002) fits and looks stock.