20' Container Door

This is an "add-on" to an already excellent model posted by Depronized on March 4, 2017. This is his OS-Railway - fully 3D-printable railway system! (Freight car) which can be found at:
http://www.thingiverse.com/thing:2152351.

I have begun printing several of these flat cars and containers. I realized that his container did not include a door, so I decided to create one. This is my efforts after looking at several pictures of 20' containers online. I drew this up from scratch in TinkerC