In addition to the gray chip shown on the ChipGuide, there's a group of Broken Drum chips on eBay - set of 4 (2 blue, 1 red, 1 gold) all on the "Hearts & Dashes" mold.

See this listing:
https://www.ebay.com/itm/276805970781

Title says "Casino Chip Las Vegas Nevada / Rare / Broken Drum x 4" with a buy-it-now price of $5000. Offered by Thunder Snow LLC.

Personally, I know nothing about the chips, their attribution or use, etc. Just bookmarking other colors that exist.