One of the last places we look when trying to fix poor reception problems is at the thing we see every day: the antenna!
Unless the chrome base for your antenna mast is gouged up or pitted, the average restorer probably wouldn’t bother doing much more than re-oiling the telescoping mast sections and maybe cleaning up the plug contacts that go into the radio’s antenna socket.
The problem is that over the years, brush-type car washes, rain and fender benders all stress the delicate electrical connections that are necessary for receiving the best possible signal from radio stations.