In November 1973, my parents visited my grandparents in PA. During the week they were there, my mother took daily walks on the Northern Central railroad track. On one of her walks, my mother found two CD 732 threadless insulator. Details on the first CD 732 insulator are as follows:

CD-732 No Embossing - MLOD / Button Mold - Green - Measurements: 74 mm Wide x 106 mm High.