Nice clean part, looks almost new old stock, NOS, but likely a part that was removed when the car was nearly new.  This is the filler cover name plate blank panel emblem ornament  for cars that did not come equipped with a factory radio. This mounts in the dash or instrument panel cluster  were the radio would normally be located to fill the void.  This is a factory OEM Mopar part. For the 1954 Desoto Powermaster and Firedome.