John, So they check them in by a vet and no papers necessary. I have not been NPIP since I believe the 1970's or 1980's. I do take blood samples for a Equal to NPIP tests.
That should be all you need. Last year they didn't require to see the papers, but asked that you have them in case requested. As I mentioned I just put my number the entry form, but you could just include a copy of your test papers with the form when you send it in.
If in doubt, ask the Doug. He is one of the guys in charge of the show and his contact info is in the first post of this topic.