The chart and pics are from a chip auction catalog that Howdy did in 1997, Jill. It has some inaccuracies in it, as Howdy will agree. For instance, no one I know has seen both varieties of the dollar chip indicated in the table. I hope he will update it one of these days.

The catalog is, I believe, still in print and you can purchase one if you want the complete article on Harrahs chips.