Hey George and 66 --
So you know, the NCDMV says this (I called and asked about this topic specifically): You are more than welcome to purchase/post vintage or YOM plates on your vehicle. They do not need to be registered because the state requires you to purchase a regular plate regardless of what you have ON your vehicle. Stupid, right? Oh, and the actual plate that is registered has to be maintained within the vehicle at all times.
For everyone else --
Here is an answer about the restored plates that I got from two different states' Highway Patrols: Some plate restorers are of less than honorable repute, and have been known to restore plates with materials that can not be registered by traffic cameras and such, thus making it more likely for the plate owners to break laws. Not always the case, but often enough the case to warrant a ban on them in some states.
Just some info to chew on...
Randy
