Dad was on the Westbound "San Juan" when he shot that movie at Gato showing the Eastbound train sitting at the station. The meet was made west of the bridge, but the siding was blocked by stock cars, so they backed out after the Eastbound passed and continued West. Dad and his buddy Preston Johnson got off the train and shot the meet;

and the parlor car "Durango" with the "Shavano" drumhead as it passed;

You can see the silver end of the bridge in the background. He also shot a movie going through that three-span bridge;

So, perhaps the ends of the bridges had been painted silver in 1947 but the rest of the bridge was still black?
Best regards,
Wayne Hills