The diamond stacks or HOLLYWOOD stack as they are some times called were for movie use. Movies like "Butch Cassidy and the Sundance Kid", or "Night passage". The stacks are just sheet metal covers that fit right over the original stacks. They would also use box covers over the headlights to make them look 1880ish. Back when the Silverton train was still run by the Rio Grande they just left them on for awile.The D&S puts them on every once and awile for photo specials, of if 473 is done up in the Grande Gold paint job.