I never knew that anyone did this until Oscar mentioned it. So it's possible that someone would buy a batch of chips, 150-200 for example, then mill the center and make generic chips or label them?

I just took a look on eBay and someone is selling Flamingo chips, clearly up front, as Milled and Labeled.

Here's another interesting set, but they don't say anything and for a fantasy chip, they have an unusual mold design. "Paulson (H&C) Chips"

What do these chips say around the center?

https://www.ebay.com/itm/285076188036?hash=item425fdd6b84:g:KOYAAOSw0JljmkS3

Just for interest the same seller has two other large sets.