Funny how first thing we'd do to our muscle cars in the 70's was ditch the factory AM radio and install a decent aftermarket one. Mine came without a radio because the kids I bought it from insisted that they keep their aftermarket stereo, having junked the original. A few years later I bought a factory AM radio from a junkyard just to fill the hole. I don't know or care if it even works, I doubt I'll be able to hear it over the engine noise if it did.
I wonder if anyone has tried to replace the guts with that of a modern radio. It would be pretty tough to get the original controls to work with the computerized modern interfaces.