Last year I ordered the patent wrapper for US4322074A, which has a ROM dump of the Mattel game Gravity. I also ordered the patent wrapper for US4162792A, which covers Auto Race and Football. That one has 6502 source code for the prototype of the Football game, but some data tables are missing and there's no description of the hardware.
I emailed the person whose name is on the printout, and he replied and told me that he custom-built the prototype and wrote the code himself, but was hesitant to send me any of the missing files.
I figured out the hardware by reading through the code, then built one. I filled in the missing pieces of code and fixed typos until I got it to work. There are still a few tweaks to make and some features could be added, but it plays pretty well.
I put all the info here: http://www.seanriddle.com/footballproto.html