These are all the chips listed in The Chip Rack, 11th Edition (just added the $100 to my colletion).

Questions:
1) The first set of chips is the first issue from 1969. I find it strange that they issued a $100 chip but no $25 chip. Is there a $25 known?
2) The second set of chips is the second issue from 1971. This set has a $25 chip but no $100 chip. Is there a $100 chip known?
3) What were the ND chips used for? Zimba was licensed for roulette and that was my first thought but would there not be other colors? What other game might they be used for?