I am currently in the process of designing an OSPi enclosure that will also have a 20-character per line, 4-line, LCD. I too plan on using Ethernet wiring and will open up the right side for full access to the Ethernet and USB ports. I design in OpenSCAD and will eventually upload my design to Thingiverse, including the SCAD files so people can modify it if need be. I like to use heat-set threaded inserts for screws. As I’m in the design phase, any input may be helpful. My photos were too large for the attachments limitation, so I have a web server I use for hosting my photos with links to 3 views of my current design.
https://we6bb.net/images/OSPi/View1.jpg
https://we6bb.net/images/OSPi/View2.jpg
https://we6bb.net/images/OSPi/View3.jpg