The device's case 3D model is now complete and printed :
I did not add buttons yet (only holes) because I don't use them actually : I recenter the device using a VoiceAttack voice command, and the case needs to be open to use the 2 other modes. I may add them including micro-USB and serial pins door access later if I ever need them.
STL 3D files have been included in the files section.
Edit : I also added the Sketchup file if someone ever need it.