Here's an idea: Before calling the FBI and wasting their time. Why don't you ask to see the books. You don't have to invite him in. If he's selling he'll show them to you in your driveway. After two minutes of his canned presentation with a foreign accent you will know if he is legit or not.
Personally, I love the idea of europeans coming to America to learn about capitalism.
"The man would not say what company he was with or produce identification."
After this, do YOU still want to see his books? I would think this would speak for his legitimacy. The only reason I would listen to his canned presentation would be to stall him long enough for the FBI to get there.