The parts were modeled from a beat up Star Wars Racer cartridge using trusty rusty calipers. Different from original in these ways:

• There are M2 nuts and screws for the PCB and shielding.
  • Use 2 standard M2 nuts and 2 M2 x 10mm screws
• There are M3 nuts and screws to close the shell.
  • Use 2 standard M3 nuts and 2 M3 x 12mm screws
• The bottom back recesses are wide for console compatibility.
• Internal ridges allow for case parts (original and printed) to be mixed and matched, though M3 screws and heads will not fit in original back shell holes. Could squeeze hot glue in front case holes and gently screw in gamebit screws while still hot.

I've printed a few in PLA at .2mm with build plate support, important for front and back case lower corners.

Interior nut slots are tall for easy assembly but can be a little loose.

This was modeled in Onshape and the file is available to be copied etc.