Casting for Hallmark’s upcoming backdoor pilot, “My Gal Sunday” has been in full swing, and three of the series’ major players have finally been confirmed: Jack Wagner (Frisco Jones, “General Hospital;” ex-Dominick Marone, “The Bold and the Beautiful”), Cameron Mathison (ex-Ryan Lavery, “All My Children”) and Rachel Blanchard (“Clueless;” “7th Heaven”).