Print with 0.4 mm nozzle, 0.2 mm layer height and 5% infill.
Filaments used for the container in the picture:
Suitable fixing elements are described here:
https://www.printables.com/model/868593-container-fixing-plates-in-h0-scale-187/files
Files for the container wagon are available here:
https://www.printables.com/model/868570-container-wagon-green-cargo-lgjns-745746-in-h0-sca
The CAD files have been created with FreeCAD Link Branch 2023.1020.0:
https://github.com/realthunder/FreeCAD
The author marked this model as their own original creation.