Here's the other Tandy Championship Football (60-2151)
http://www.seanriddle.com/tms1100.html#tandychampfb2

I only dumped it electronically. I got the same ROM contents at 7.5V, 9V and 12V, and all 8 bits dumped fine. I also dumped just the high bits by executing each byte and shifting out the PC, and those matched. The output O PLA I dumped is very similar to the other game, so I think it's correct, too.

The wiring is very similar to the other Championship Football, so I bet both were designed by ERS.