I would think chips from closed casinos are clearly obsolete. But when a chip is removed from play and replaced, it is commonly called obsolete. That doesn't mean it will stay obsolete. The Bonanza $1 pictured below is a recent case in point. Off the tables 20 years, casino name changed, fit every criteria for obsolete we could ever have. Then there they are, on the craps table. Go figure! I think we just have to base it on the most accurate information we have available at the moment, and be prepared for surprises.