HO Scale Coupler Box - Single Screw

This is a modified version of https://www.thingiverse.com/thing:4737909 that uses a single 2-56 1/8" screw to hold the cover on. It screws into the center post. I was having clearance issues with the original model as my wheels kept hitting the screws, so I removed the side screws and moved the screw to the center.