Here is a Atari 2600 Cart PCB. It is the basic 2K/4K EEPROM. I don’t have the PCB files uploaded yet but you can download the CAM files. This is free for anyone to use, sell, and/or distribute.
I will be uploading the PCB files in a week or so when I get back from my vacation. I use FreePCB. I will be uploading my custom footprint library as well so people can open the files.