Fender tag addition?

I went and looked at a '65 dart GT today and when I got home to decode the fender tag I noticed the paper addition stuck underneath. Anyone familiar with these?

Like Keith said I would think the tag is made out of thin brass. It could well be a tag they started use on 66 model but I'm not sure. However another interesting fact is that the car was assembled July 30! That is probably one of the last 65 Darts produced. If we had the first four digits or letters off the VIN we can determine which plant it was assembled at.