This debate got me curious. I called my states enforcement number to pose the question to them. I am in Kentucky. As far as Kentucky is concerned the legal/proper way to accomplish this is to apply for a duplicate VIN. They have a form for it. The alternative solution is to apply for a new VIN plate. They would send you an new modern VIN plate that you would attach to your vehicle someplace else. It would have a new VIN number and a replacement title with the new VIN would be issued. You could then change your repo door tag as much as you like. It is no longer the legal identification tag for your vehicle. It is simply a period authentic serial number for looks only.