There are software programs available where, given a name, license plate, address, etc., or DL number, lots of stuff is Public Information. As so, it is readily available for a search fee.
No accuracy gurantee, or if the information that is provided to the search engine is legit, or not. GIGO.
See if your Credit Card agency has an option for Fraud Protection. Looks as though you might need it.
Given some time, you can untangle the buyer, seller, FFl issues. Right now, I'd do the Credit Card Equilavent of a 'Stop Payment'.