These are prototypes of Atari alumni Alan Murphy's that I archived several years ago. He was the graphics artist for Taz-Mania. I'm not sure what involvement he had with the Sega Channel carts. I don't know how different they are from the released versions, or if all of the Channel carts were even released, but hopefully some Genesis experts will chime in. Here's what I have:
Sega Channel 01
Sega Channel 02
Sega Channel Game Guide
Taz-Mania
Sega Genesis prototypes