F&C makes the GN 8000 series of DS 40' Boxcars with hopper bottoms. I built the kit, but chose to do it as the later non-hopper rebuild. The kit comes with a bazillion little parts that would be used to mock up the hopper doors and linkages on the underside, including different queenposts. I've used those unused parts on numerous projects since by slicing and dicing them for things like brackets, clevis, door stops, etc. The kit just keeps on giving. I chose the non-hopper version after research with this group many years ago that by my era they were pretty much hanging around the home rails for use only during the grain rush.