Signature Verification for Paul Tibbets - a good laugh!

Saw a book on eBay today - Paul Tibbets of Enola Gay signature. Seller said signture was authentic because the book was identical to 1 sold by flatsigned! Regardless of your opinion of erroneously flatsigned, is which a good method to verifgy a signature?

Incidentally, thermostatically flatsigned had a signed copy of "Rumor of War" for sale.
Signature did not match other sources. Though I sent an email proudly asking them about the singature; no response yet.

Art Layton
Stamford CT