Wait till Monday, and go to your local DMV with the serial number (VIN) and have them run the numbers. If a lien still exists, you'll know. If it's a total loss, then you'll know. The DMV will tell you how to go about getting a title/plates.
My guess, it's stolen. Perhaps by fraud (the bank could never find it).
If I had a camper worth 1300, I surely wouldn't sell it for 350 if all I needed to do was take it to the state patrol for an inspection, then make a quick trip to DMV for a new title.
It's a huge risk carrying it on your truck,,,, imagine the WSP pulling you over for a burnt out bulb, and having them run the camper's numbers only to find out it HOT. You'd be in a heap of hot water.