Jeeeze Louieeeze, all this makes me happy my S4 came with a poorly installed aftermarket radio that literally fell out of the dash.
Since I didn't want a radio in my car this was fortuitous.
I'm with you. My 79 came used, with what I assume, is the original Blaupunkt cassette radio. Reception was never very good though I could get a few channels, but I didn't even try the cassette deck as I have no idea if I even have any cassettes anymore. The aerial has frozen in the mostly down position from lack of use (I may unfreeze it to get it all the way down).
The car sounds great on its own and that is all I need.
Perhaps if I decide to sell it, I will put in something after market just to say it has a working radio.