poke around this page for a while to see if it's an OEM ornament, then see if you can find some old JC Whitney or Western Auto catalogs, if it's an aftermarket ornament. http://www.taillightking.com/index.htm
Beat me to it, Jim- we had a '51 four door Kaiser for a while! Picked it up and drove it from Ohio to Philly, and it was great on the turnpike, but I started getting tired, so I took Route 30 right around Gettysburg- BAD IDEA! It had bias ply's and old brakes- both the tires and I were screaming around every corner
If I remember correctly, there is a hole for lighting- don't know if all models were lit or only special models like the Dragon?