Eighty years ago this month, the March 1938 issue of Radio Today carried this ad for the Admiral Model 55 Auto Radio.  The 5 tube superheterodyne featured five preset buttons.  Unlike earlier models in which each button contained a tuned circuit, in this one, pushing the button moved the main tuning dial.

Some competing Delco models from three years later are shown below, from the 1941 catalog we showed a few days ago.