Disney-ABC TV today filed paperwork seeking approval from Los Angeles County for a huge 56-acre production facility on property it has long owned in the Santa Clarita Valley. It would include a dozen soundstages, almost doubling the number it has now in LA County. Predictions are for a $533 million economic boost to the region and about 2,854 new full- and part-time jobs. It’ll be called the Disney/ABC Studios at the Ranch, located on the western edge of Disney’s 890-acre Golden Oak Ranch.