Chrysler AM/FM 3501623 Radio

Another possibility is to remove the wires from the AM/FM switch inside the radio at the end of the broken part. Mount another switch on the bottom of the radio and attach the wires to that switch (Maybe Ward's would do this for you). It might be a little cumbersome to reach up under the dash and switch bands but if you mounted it near the back of the case on the bottom you should be able to reach it without too much trouble. It retains the original appearance too!