The Sumpter Valley cars were built in 1917 by the American Car & Foundry plant at St. Charles, Missouri. The ACF order list shows that the order was entered on January 19, 1917. This cars were built with steel underframing and steel framed ends. The as-built interior treatment was similar to the UP/SP "Herriman" design coaches.
Framing for coach (or combine)
Interior view of coach
interior of RPO apartment
end view of RPO car
All the above views are scan of prints purchased from the late Frank Ellington who had shot copy negatives of many ACF builders photos and sold copies.
Brian Norden