Can't say if he was a 'salesman' that far back or not. He wouldn't have been making them himself but may have sold them.
One other possibility is this - with the exception of Hotel Nevada, BM where we know he definitely supplied them, I believe all other casinos he made after the fact chips from were closed. The Truck Stop did of course change name rather than closing so the fact it was still there might have also made him think to cancel them.