Hi Don,
Andy answered your question involving where the Sports Book is in the GN, I will try to answer the other part of your question.

Before Nevada's Regulation 6 was brought into similarity with the federal money laundering statutes - the $10,000 dollar cash reporting requirements could be circumvented by using large denomination gaming checks (chips) instead of cash in paying off a wager.

ALL sports books had these large denomination checks to pay off wagers with. Sometime last year Nevada's Reg 6 was changed making payouts with checks the same as cash. The sports books no longer needed these large denom chips since they were now considered the equivalent of cash.

Hence, many houses are now taking efforts to cancel and remove these chips from their cage and accountability. In fact Binion's has issued a notice that after the first of the year their $5,000 chips will no longer be redeemed. I believe this is why you are now seeing many oversized - high denomination chips, cancelled with a hole or notched, being made available to collectors.
Hope this information is useful. Best, Jim