I don't know how David Moors managed to do it. My harvesting story about that one:

I saw some in the Cage and asked the man if I could buy one. He said, "Maybe but first let me finish my count" and went back to his bookkeeping chores. When he was done, I approached again but the made the mistake of asking in front of the Casino Manager, who had come in to review the tally. "NOOOOO!" he yelled. But then, maybe feeling a bit of shame, he asked, "Do you have our Grand Opening $5 chips?" I said I didn't know they had any, to which the Manager said to the other guy, "Oh, look in that drawer and sell him a few," which he did. Sort of a "consolation prize."

As I remember, they were using two different green drop chips at various tables, one a generic and one with the typical casino logo. Now you have to look for TWO chips.