With the 40th anniversary of the death of Marilyn Monroe approaching on Aug. 5, the author of another book on the screen icon has a new wrinkle up his sleeve when it comes to selling his tome. Actually, it's not a wrinkle at all, but a genuine lock of Marilyn's hair – "a short one of nearly a dozen strands," "Marilyn By Moonlight" writer Jack Allen told PEOPLE.com Monday afternoon. The memento was clipped off her head shortly after her corpse was sent to the Westwood (Calif.) Mortuary in preparation for her funeral. "The body was pretty beaten up after the autopsy," says Allen. (Monroe died at age 36 from what was officially called a suicide from an overdose of sleeping pills). Legendary Hollywood hairdresser Sydney Guillaroff "did her hair for the funeral," explains Allen, "but it was all matted with formaldehyde, so he clipped it and called the Fox wig department . . . so she'd look good in the coffin." It was the mortuary owner, Allen says, who "dipped into the trash" for the hair clippings, which he then "gave away to eight close friends as a keepsake." Allen says that he secured his blonde lock last year from a fan in England who had purchased it from one of the original owners, and that the lock has been authenticated as Marilyn's. Furthermore, it is to be raffled off at L.A.'s Hollywood Entertainment Museum on Aug. 5. "This is the first time a book has ever been published with a lottery ticket in it," says Allen, who compiled his heavily illustrated coffee-table book with the aid of the West Coast-based "Marilyn Remembered" fan club, many of whose members, he says, knew Marilyn personally.