Hi Bill,
Looks like you are on the right track. The power supply is usually the culprit in the old radios. No-one uses the old mechanical vibrators anymore. The solid state units are the ONLY way to go. The downside is that the new SS vibrators are non-for-giving, if the load is too heavy or they are hooked up backwards they are destroyed in a flash. It has always been common practice to replace the buffer condenser when replacing the vibrator. The buffer is most likely what destroyed the vibrator. With the SS vibrators, it is even more important. While you are at it, the OZ4 should also be replaced with solid state units. And, to complete the job, the condenser across the primary winding of the output transformer, along with ALL paper condensers should be replaced. If any of the bypass condensers develop a short away goes the SS vibrator.
To restore a car radio many other functions are performed by the technicians such as lubrication of all the dial mechanisms, freeing the pushbuttons plungers, cleaning the volume/tone control, lubrication of the switch, electrical alignment of the IF circuit, ect, ect.
