If the unit was misrepresented, you may be able to get out of the sale. Has money changed hands? How much? What is the sellers feedback? If he's been legit in past auctions, he may want to preserve his feedback rating and will work with you.
As for the title, I have used Broadway Title in Georgia (ads in Hemmings) to procure a title for a 60's Airstream that I bought several years ago. You will need a bill of sale. They then go to a state that only needs the bill of sale and they are able to get a title from that state which you then take to your local DMV to get titled in your state. If the trailer is/has been stolen (especially if registered at a prior time in your state), it may come back as such when doing all this title work - maybe not. Mine had no issues at the time.
Keep us posted on what's happening and Good Luck either way you proceed.