[Arran]

Phill;
I had a look at my Riders "Specialized" car radio books yesterday, I don't have one that covers Studebaker, one was for G.M Delco radios, the other covered Chrysler MoPar ones, which were made by Philco and Motorola, but I did have a look through those since there may be similarities to the 1955 Studebaker one. I also had a look through the Radio College of Canada books for 1954-55-56 and they only have G.M/Delco listed for those years, occasionally they have listings for Automatic and Motorola car radios but nothing for Philco car radios. This was why I was asking about the tube lineup in the Studebaker unit, does it have one chassis or two?
From what I remember Studebaker came out with all new bodies for 1953 in both sedan, and coupe style, which they facelifted until they closed down in 1965-66. Chrysler car radios were the same from 1951 to 1954, in 1955 they changed their bodies across the car lines, except for the trucks maybe. I'm thinking that if the vibrator transformer is shot that you could probably use one from a Philco car radio with the same tube lineup, Chrysler, some Plymouth, and some Dodge model care radios were also made by Philco. Another thing you might look for are replacement car radio vibrator transformers made by Hammond, how common they are NOS is another question.
First I would confirm that the transformer is actually bad as the vibrator and rectifier tubes are the weakest points in the chain should a filter cap short out. Philco did not make car radios with a synchronous vibrator so you don't have to worry about finding another one of those.
Regards
Arran