Expanded VIC-20 Cartridge

Work-in-progress modification of my earlier VIC-20 cartridge model (http://www.thingiverse.com/thing:69261), to be able to hold at least a DIN connector (http://www.thingiverse.com/thing:104160) in the back. Will upload the openscad code once it's finished. Note that I only modified the outside of the cartridge for now.
Suggestions for improvements are very much welcome. I personally would want to use several screws to attach the two parts together, instead of the regular, more fragile, clips.