This week, nearly a half-century later, the PBS show "History Detectives" will help the two fans find out if their Beatles autographs are real …
… or, like many celebrity autographs floating around the Internet memorabilia market, 100 percent fake, not worth a dime.
John's widow, Yoko Ono, gave Ken Hoffman a framed, autographed copy of "Plastic Ono Band."
Lennon's autograph is the most collectible and valuable of all the Beatles', according to the show. Depending on its condition and what it's written on, a Lennon signature is worth "between $1,000 up to $100,000."
The market for Lennon memorabilia is booming for several reasons.