I have received this part after some family friends had finished cleaning out their garage. One of their Uncle’s owned a service station in the 40's-50's as well as a radio shop.
I am thinking this is a horn button; there is a gold knight figure in the bezel and no other markings present.
http://i49.photobucket.com/albums/f2...2/IMG_0137.jpg
http://i49.photobucket.com/albums/f2...2/IMG_0138.jpg
http://i49.photobucket.com/albums/f2...2/IMG_0140.jpg