That will be most likely hard to find. The original switch panel was mounted in a recessed plastic housing. They usually didn't last long. I never liked the recessed switches on mine because they were hard to see. I would just custom make something if it were mine. Here is what I did.
This is what I had and most likely what you had.
Here is what I did.
Let me see if I still have the original plastic insert. You might be able to use it as a mold to make a new one. I doubt I have it but I will check.