I try to remember when they ask if it is real that they are asking because they like it and just want to engage you in conversation about it. They really don't care if it is real or not. If it is super fast they might brag to a friend about it.
Some folks here complain if a replica is called a Hot Rod. I say why? Shel himself called them Hot rods built by a bunch of Hot rodders. Of course it is a Hot rod.