Wow. Those are cool. I would guess that they are cancelled chips. Test chips or floorsweepers usually have the same stamp at different angles. It looks like your chips have the casino name on the base and then generic stamps printed on top of them. Kinda like how Paulson cancelled chips with their starburst stamp.
However, this is just my opinion. The only thing that makes me think they are might be floorsweepers is that you have so many of them in the same color with the same stamps, which leads me to belive they could be test chips.
So to make a short story long....

I don't know.
- Couga