Does yours have horizontal wear lines around the inside? And, do those wear lines align with the chips?

They do look like they would align closer to token vs chips.

I'm betting that those wear lines will align with a stack of 20 $1 slot machine tokens.

I just tried to load 20 tokens......it only takes 19!

The only reason why I ever thought they would have been for chips is for 2 reasons:

1. I got my MGM in a auction years ago with 3 MGM Grand Reno Chip in the holder.
2. The cup/tube holds 15 chips and the width of the holder is the size of a chip...and not a token.

My guess they were used to hold chips and tokens.