Now and then someone would make up some metal slugs and hope their weight would allow slot machine use. One of the attorneys I work for prosecuted one such crook, many years ago. He was caught by casino security after he deposited the fake token and merely walked away when the machine did nothing. It was correctly assumed that a real player, using a genuine token, would complain to management in such a situation.

Not saying the token you show is definitely a fake, but such things are out there, even today.