Mark,
My thoughts are, unfortunately, a lot of show car judges might be knowledgable, but fewer can tell an NOS part vs a repo. For instance, how many people even reading these forums can instantly tell you what the differences are in repo vs original plug wires, radiator caps, radiator cores, battery cables etc? And this board is full of very sharp people!
There are some VERY good repo parts out there, but there are always minute details, that only someone who studies both parts in fine detail, would know. I think the cars using NOS parts vs. repo parts is what actually seperates not only the class-but the judges!