I recently came across this Lucite embedment of a Harrah's, Las Vegas, Grand Opening chip (CG328043, TCR #D0266.LT) and a signed Certificate of Authenticity.

I have 2 questions.

1. What is the "Certificate of Authenticity" for, the Lucite embedment, or perhaps something not included?

2. Why is there a conflict with the embedded chip's "Grand Opening" date of "October 23, 1997" and ChipGuide's Opening date of April 21, 1992?

(This was a thrift store find here in Las Vegas.)