Teen-Age Diary Secrets #6 has a photo cover, the young lady is Norma Jean Mortenson (Baker) later to become world famous as Marilyn Monroe. a raw Fair 1.0 copy just sold through mycomicshop.com auctions for $1,000. this is one of two known comics to have a Marilyn Monroe photocover from when she was still alive, both books should be considered Major Keys.
the other book is Sweethearts vol 1 #119 (by Fawcett). it features a still shot from a movie starring Marilyn and Richard Widmark.