E. F. Johnson Company Radio Advertisements for 50th Anniversary. Material: plastic, metal. Size: 4 1/2" diameter disk. Description: plastic case, metal CD; CD contents: Waseca E.F. Johnson Company employees announcing E.F. Johnson Company 50th Anniversary Open House Celebration; note with CD: "Radio Spots, E.F. Johnson 1973 Open House"; length: 5 minutes, 42 seconds.