Fully working container for MPO-2: https://tinkercad.com/things/bukYI1dg6n2
Use CA glue to assemble: http://www.amazon.com/gp/product/B0000DD1QO/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B0000DD1QO&linkCode=as2&tag=i08bdb-20&linkId=NVH7FLLJEJXCF7BN
Use CA glue accelerator if you don't like to wait for the glue to dry: http://www.amazon.com/gp/product/B0068QEBAU/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B0068QEBAU&linkCode=as2&tag=i08bdb-20&linkId=ZDQJ4CDDEO5Q7AQ5
Locking mechanism rails are sections of cut-up, straightened out 1.75mm PLA.
When printing the "cargo-container-base-bottom-large.stl", pause your printer and change filament to a wooden one, before it starts printing the top-most sheet of plywood to create a more realistic, multi-color print. Here are a few of my favorite wood PLAs: http://amzn.to/2skTUgU