These could very well be Prototypes, and could have been made for the owner of the mold (Hilton Las Vegas?) to show what a proposed new chip or series of chips would look like. Might be sufficient to show chip colors and inlay colors even if the inlay doesn't match anything proposed for Las Vegas. Unfinished edges are typical of prototype chips made to help a customer visualize what might be delivered to him. If somebody comes up with written documentation from this period, we might want to make the comments more detailed. Don't want these confused with the Fantasy chips that Paulson made later to simulate chips for Cuban hotels.

That green $20 baccarat chip (N4554) that Rich showed in the initial post was definitely made in prototype form with unfinished edges. It has a Hilton Las Vegas inlay, of course, so not really the same situation. It was made by Langworthy, not Burt and I bought one from an informal auction that Howdy held in the 90s at Gamblers General Store. It gets complicated .

Here is a page of Hilton prototypes that I got from a chip show (JohnC?). It shows several different ways the salesman had of showing the customer what his chips might look like. Some of these have just a blank white inlay with the denomination written in. Some are notched, some have unfinished edges.