Does anyone know where...

I've run into this before also. In one case, I just made some rosette looking rivets out of some regular ones and popped them into the car to satisfy those DMV knuckleheads. If you want to keep it original looking, maybe you can find a broadcast sheet in the car somewhere. That will have the VIN and shipping order number on it. The shipping order number is what is stamped into the body....usually on the radiator core support under the antifreeze or battery sticker. Some cars have them on the trunk opening lip and firewall also. Another option is to contact Chrysler historical and try to get a copy of the original IBM card for the car. It has all that info too.