Thanks. I bet you are right on both accounts. I'll check the speakers and see if they are hooked up. The radio doesn't work at the moment, so I haven't had a chance to try out the speakers. And the the plastic part is about the right size for the door switch.
The one I used was a part from Rock Auto, PN 1S1016. But I had to fashion an adapter terminal to connect up to it. If you buy that part, let me know, I'll make one up for you and mail it off. The only other problem I had was that these are supposed to be "self adjusting" when you close the door, it bottoms out and slides the barrel to the proper location. The switch wasn't perfectly perpendicular and the barrel buckled when I closed the door, which prevented it from sliding, resulting in a ding in the mating door surface. I wised up on the replacement part and used the drill press to press it to the proper depth before installing it. I took a measurement off the good side.
Good luck and thanks for the feedback.