Mark talk about the seven jewels that had belonged to the Czar of Russia being openly sold to collectors. No one could have legal ownership of the jewels (having been presumably stolen from the Czar) so they could not be sold on the open market.
Inspector Churchill uses a $1000 bill to entice a tobacco shopkeeper to give her information. The problem is, bills above $100 were no longer legal tender in the U.S. as of 1969 (however, they do have collector's value - see comment by someone else under Trivia). FACT CHECK: All high dollar bills, including the $1,000 bill, are still legal tender in the U.S. though they are no longer produced.