When Intermountain came out with their 70T flatcar I negotiated a "bulk buy" of the Protowest kits.  I always thought they built into nice models and I was using them as the basis for DT&I flatcars that got modified and used on the Ann Arbor RR.  Bulkheads were added to four of the DT&I cars and others got modified stake pockets and side racks for hauling telephone poles.  Jim Hediger gave me a copy of the engineering drawing for the pole cars and I built two using tiny bits of styrene (9 pieces per pocket X 20 pockets per car . . . after therapy I am doing MUCH better now . . .).  I would do more of the pole cars if I could find someone to 3D print those parts now.  The bulkheads were scratch-built from styrene and added to the Protowest cars.  Photos attached.