https://github.com/sparkletron/Colecovision_Controller   The github link above is for my finished project that has all the files to create a 3D printed Colecovision controller with all the original functionality. The form factor is the size of a NES controller. It uses micro-switches, single sided PCB, diodes, #4 pan screw, 3D printed parts, and a Sega Genesis extension cable. This is available with no license, do as you please with it. All files are available in the github repo.