I have some games that have variations on the end labels. It would be nice to document them here by uploading a photo. It would also be good for recreating/reproduction end labels in the future. The systems I can think of off the top of my head are Atari 2600, 5200, 7800, Colecovision, NES, SNES, & Genesis.
If you are going to do that, maybe you could add a 'misc' artwork slot or two at the same time. Sometimes the back of a cart may need documented along with the front, or other things.