I hate to be the one possibly bursting your bubble...but my understanding is that outside of a couple small groups of bikes that were built in the US, PDG Series Paramounts were made in Asia.
So you either have a real rarity on your hands or else just a really nice Asian built frame (not that there's anything wrong with that
). Dennis Kilfoy is still around and making custom frames - I'm pretty sure he is somewhere here in Florida. If you search him out, maybe he can confirm the seller's story or give you the real info about your GF's new frame.
Good luck and have fun...