I have an 82 Toyota Pickup and on the ON/VOLUME knob the post is broken off. What I’m calling a “post” is the piece that rotates when you twist the volume knob and slides in to push for on/off. I’m not sure what the technical term for the part is, which doesn’t help my search confidence. I’d like to just replace this piece if possible to get my stock radio working. Do any of you have a source for parts, or a bad radio laying around?