In as much as there seems to a rash of 'missing' VIN's and VIN swaps lately, ...there are times were for whatever reason paperwork gets lost.
I had just this case about 6 months ago for a '67 I purchased. Prior to purchasing the car I contacted DMV (NY), and went from there. As DanZ10 mentioned, ...be prepared to make multiple trips to DMV, ...the requirments on what paperwork you need completed differs depending on who you talk to.
Anyway, ...if you're serious about the car, ...start with DMV. Get ALL the DMV forms NC requires, ...and fill out as much as you can. HAVE THEM WITH YOU WHEN YOU PICK UP THE CAR, ...and have the seller sign wherever it's required. I even went as far as including digital photos of the VIN tag and the car itself in printed Bill of Sale (MS Word document).
Quite a bit of paperwork, ...just be prepared for it and it really wasn't that bad.