Greg,
According to the Pit Boss (I called him minutes ago and asked all about the
game) at Kickapoo:

The game was never called Natural Texan (it was actually the PLAYER who was
a Natural Texan), but the game was always Kickapoo 22. The game was retired
from the Lucky Eagle Casino a little over two years ago. The BONUS for BIG
TEX was $25 he thought, but not absolute. This game (to his knowledge) was
never played at any other casino. The 4 BIG TEX buttons are ALL that he
knows to exist! He knows of NO Natural Texan Chips (at the casino). The told
me he searched the casino for a few days and could only come up with these
buttons, and NOTHING else relating to the game of Kickapoo 22. So looks like
you own 25% of all the known buttons! He says he thinks all the
buttons were destroyed, since they were retiring the game and not planning
to ever bring it back. Don't lose that button! They look even BETTER now
that there are believed to be only FOUR huh? hahaha

The 8 Card "BIG TEX" button:
Was used when Kickapoo 22 was played. When you played a hand which you took
8 cards and were at or under 22, a "BIG TEX" button was placed on your hand
and no more cards were dealt to you. Once the rotation to the other players
was complete, the dealer paid the winning bets and anyone with a "BIG TEX"
button was paid a 'Bonus' ($25 chip) plus won the hand automatically, by
virtue of the 8 Cards taken.

The Natural Texan Button (just as you report -- except the name of the game)
Was placed in front of the player for each consecutive two card 22. Reaching
3 buttons paid $100, reaching 4 buttons paid $500.

This Help?
Mike