I've known that Heath offered a Pong game for thier sets, and that Maganavox was the first to market with this....but I didn't know that Magnavox sold a set with the game built in! See below picture that I swiped off this site:

http://www.pong-story.com/odyssey_other.htm (scroll way down)

Here's mention of the Heathkit system:

http://www.pong-story.com/heathkit.htm

If anyone has or knows of any of the Heath games for sale please contact me directly (check my profile for addy). Thanks

Anthony