Back when the Pueblo Locomotive and Rail Historical Society was in business one of the plans was to have Santa Fe Northern 2912 operate through the Royal Gorge on a lease. Since the engine was never rebuilt that plan went by the wayside.
In other news the major drawing card of the Royal Gorge Route is the Gorge itself. The train has no competition going through the gorge. From Parkdale west the railroad parallels US 50. There is nothing extra to attract a non-railfan (who buy the bulk of the tickets) from riding beyond Parkdale.