This is scaled remix of "2 Plank Open Wagon for 16mm Scale Garden Railway" by arockStone: https://www.thingiverse.com/thing:2721704
I've just scaled it down to 1:87, added the ram, the buffers and the coupler boxes as per NEM. I've also added a spool of wire to load the wagon.
Since I love to work with wood, I've made the spool sides out of matches, but it was very time consuming. So, I designed standard spool sides to be printed.
The wheel and the couplers are factory made.