Fender Tag
The vin tag on dash is mounted with rivets, black rosette rivets to be exact, which you can still buy nos or reproduction. Usually the front windshield needs to be extracted inorder to access the vin tag to put in rivets.
The fender tag I would be inclined to use phillips machine bolts and some sort of locking nut underneath, so someone doesn't steal it.
Not sure what type of Mopar your looking at, some have the vin stamped on the upper rad support driverside and some have a sticker on the door jam with the vin.