License plate on Truck? or camper (with overhang)?

You go ahead and try making a photocopy of your license plate and see how far you get. You're making a fake plate. Counterfeit license plates are illegal even if the legit ones are right there on the truck.

Common sense has nothing to do with it. The litmus test is if the cop has to expend extra effort, no matter how little, to verify your license plate. You want to avoid notice, not attract it, and a paper license plate will attract attention.