When the supply of GE radios was exhausted, KF switched to a Delco unit which is the one in the latest photo. This same radio was used thru the end of production in 1955, but in 1954, the push buttons were changed to black and the knobs went to black plastic with chromes inserts.
1951 Kaisers with the GE radio have a bump out in the firewall to accommodate the longer chassis, once the Delco radio was used, the bump out was removed.