No problem with questions, Alex.

"just what do the regs say about the chip inventory?"
I already told you this, above.

"Does it matter whether the issuing casino remains open?'
Yes, if you are staying open, you will follow the GCB suggestion.
Do you have to? You deside.

"What does "proscribed by the Chairman of the GCB" mean?
Your guess is as good as mine.

"Does he/she change his/her mind from time to time?"
Your guess is as good as mine.

"If a single owner decides to shut down and retire (never seek another license)and the redemption period passes, then is there much downside to not destroying the inventory?
Yes, when a rack gets out, many will be passed at other casinos. Floor personnel will Ok almost anything for play including James Bond chips. Change girls will also take them. It is a loss for the casino.

If you call and ask the GCB, they will tell you to destroy them.
If you don't call ??????????
A casino staying open does not want cancelled chips floating around. Their own employees will cash them in for play and change. They would also look bad at other casinos if a bunch got cashed.

I wanted to notch some LE's at the FQ's and sell them in the gift shop. GCB said absolutly not. Put them in lucite or destroy them. We destroyed them.

If a casino is smart they will call GCB to find out what they want you to do. With so much flexability in the regs, it can be hard on a casino that does not call. I always call and get an opinion if I am not sure.

I know the answers are not what you asked for, but it is the best I can give.
There is flexability in the regs.
The main one goes something like this, " If we forgot anything in the regs, the chairmans decission is final on them, also." <g>