Your questions are a reason that I'm against any universal numbering system for casino chips. I think that we need regional specialists and experts, and they need to be recognized for publishing their reference books on their regions by having hobby-wide acceptance of their reference numbering systems. To some extent, this system can help prevent outside profiteers from providing materials to the hobby without doing the work required to claim to be experts on any region.
....maybe you might consider sometime in the future publishing a Harrah's chip guide. They have enough casinos to be considered a distinct collecting category by themselves. In the short time you've been involved in this hobby, you are well on the way to becoming an expert on Harrah's chips. From where I sit, you're already there!