Ray Vane Chrysler-Plymouth in CA plate covers
I found San Jose, Bona Sera Chrysler Plymouth plate covers on ebay from Wisconsin
These are tough to find, I restored mine myself. There were cracks which I soldered on the inside. And model paint was by far the best to use. (Chrysler Plymouth was tiny letters. My eyes still hurt)
I do look for other California ( even southern) plate covers. I will let you know