Charles, the original radio from my Dearborn 65 hipo , with a scheduled build date of April 22, 1965 is stamped 5TMZ. The first number on the selector dial is a "6". I am 99% certain this radio was installed when the car was built since I have owned it since 84 and am the third owner. By the way, it has never worked worth a damm and will come on very loud with no warning and scare the soup out of me and just as suddenly turn itself off for two or three more years. (I call it Christine). Just a quirk that makes me smile when I think of it. Replaced it with an AM/FM which at least turns off and on when I want it to and is consistant in behavior.