A pair of DX Containers

DX containers were a variation of the standard D container, which was a larger open container than the C. The DX was intended to carry Portland Stone and be carried in the GWR O35 medium fitten open (see my model of this wagon). However, only 2 of the O35 wagons were ever built (just before WW2) and the DX containers were carried on normal conflat wagons too. There is a photograph of a DX in a small 1957 publication by British Railways Western Region, "Swindon Carriage & Wagon Works". The side is not illuminated well so I have inferred some details from D containers. Apart from the 2 containers, this set includes 2 blocks of 4 stretchers, joined together so they meet minimum bounding box limits for printing, and there are more of them than you need, to allow for breakage when separating them (use a sharp scalpel) and fitting the central wire post and a curved wire bow over the top (see photographs). Two stretchers were placed across the top of the container (reaching from side to side) in no precise location, and could support a tarpaulin sheet.   
A tiny piece (2mm maximum) of 0.25 mm diameter brass wire works for the central post, and a longer piece (13 mm) of 0.20 mm diameter nickel-silver wire works for the curved bow shape. Insert this into one of the angled holes in the stretcher and, guiding with tweezers, gently bend the other end down until it can be slotted into hole at the other end. Put the vertical piece in afterwards. Clear all the holes out by test-fitting a piece of the right wire in first, so that you can be confident it will fit in when you need it to. There is no need to form the wire into a permanent curve before fitting, it is flexible enough to adopt the perfect natural curve as you put each end in and bed it to the right depth. Plastic deformation (permanent bend) actually makes this harder to do, and the result may not be as good.
TOP TIP: don’t paint or prime the stretchers before you fit the wires in; that will make it harder to see where the holes are, and probably block them up as well. You may need to use a magnifying  loop and tweezers (see picture).