You might consider providing a cutout for a standard size picture-postcard for those who would like to customize the display for a particular casino. That way you are not providing a casino logo and there's no copyright or trademark consideration. This could be in place of or in addition to the Las Vegas logo you show.

Casino postcards are also a collectible and not hard to find for just about any Nevada casino.

I would also agree with the option to use the plastic air-tites as another poster suggested. An alternative would be a round piece of plastic sheet to insert into the cutouts in your wood frame before mounting the chip in a foam ring. This would eliminate any danger of wood finish oils migrating to the chip. The cutout would have to be a little deeper to accommodate the plastic shield.