Tom, this scheme first appeared in 1947 as original paint on 500 new boxcars delivered by Pullman-Standard in 1947. These were famously numbered 1 thorugh 500. See attached. They were all welded cars with fairly unsual "rolling pin" ribs on their ends. Some had ribbed doors, some had paneled doors, but all were 6 feet wide.
Shortly after, some of the similar, older cars purchased in 1942 also were painted with this scheme. These cars were riveted and all numbered 9-thousand something. It was a short-lived paint scheme.