Yes they are closed.

I've seen 3 distinct models of chips for sure. When talking with some vendors at the vegas chip convention the price point on the chips were wide as some had a silver core, and gold plating and others pure brass. I'd like to find out what all the version's are and the material they were truely made with that set's appart the value before I consider adding more to my collection. I know there are also many molding variations as well, showing the metal core and the vendor's process that goes into the molding.

thanks again for all the information