If you live near there. Go to the cage with a picture of the chip(s) you are looking for. If the cashier doesn't want to help. Ask to see the cage manager. Tell them you are a collector. Ask them to look for a couple of chips. Most of the time they will find some for you. You will have to pay face ( a tip is also nice) . They don't destroy any of their chips. All chips are still redeemable.
**** Unless they are fake, made at a later date and never casino issued. 😳