The casting of “Finding Neverland,” the Diane Paulus-directed musical that will have its US premiere at the American Repertory Theater starting July 23, is apparently in flux. According to Deadline Hollywood, Tony winner Roger Bart, who’s starred on Broadway in “The Producers” and “Young Frankenstein,” is out and will be replaced by Michael McGrath, a Tony winner in 2012 for his role in “Nice Work if You Can Get It.” (McGrath is currently appearing in “The Odd Couple” at the Cape Playhouse.) “Finding Neverland” is based on the 2004 movie, starring Johnny Depp, about playwright J.M. Barrie and his relationship with the family that inspired him to create “Peter Pan.” We contacted the ART, but its rep gave a curt “no comment.”Mark Shanahan can be reached at email@example.com. Follow him on Twitter @MarkAShanahan. Meredith Goldstein can be reached at firstname.lastname@example.org. Follow her on Twitter @MeredithGoldste.