They're what we used to call 'knob job' radios because they had two knobs.. generally one for tuning, and the other for volume.
I haven't seen new 'knob job' radios in quite a few years.
I'd check the local bone yards.. you might find one that got left in a vehicle when it got junked.
I have seen some outfits online selling those style radios.. intended for use in old muscle cars and such.. generally with a tape deck built in and some obscenely large Chevrolet logo on the tape door.. but they can be kind of pricey.
