Im surprised you found no proof of that.
The plaques (which were first offered here on the chipboard and subsequently in my plaque sale and on ebay) were indeed seized during a military raid.
However, the chips were not with them at that time, and the only other time I had seen any is on a Huxley table demo at a London gaming expo some years back. The $1 chip was blue. I did have a few for sale here at the time.
No clue if they ever supplied those chips to the casino but if you emailed them they would probably give you an answer, they are relatively helpful in that respect.