I took an interest in the concentric circles during my research into the chips reproduced for Carl Osborne after the casinos closed.
Whilst I will not say its a certain way to distinguish them, these facts apply for every single such chip that Osborne had re-made including the oversize Castaways.

1. The originals have concentric circles, the remakes do not.

2. Chips with circles all have slightly rounded polished edges. Chips without circles have sharp square edges.

3. Chips with circles are made of slighly softer plastic compound. Chips without circles are a harder brittle plastic.

They have to have been made using a different process. Too many coincidences.

(The only known original $100 Bingo Palace is not for sale )