Yes, I've been told some pretty bad plaque examples exist also having the cancellation on the reverse.

I'm not aware of any Italian casino having M-O-P, but years ago there was a collector who used to travel in Italy with his son in search of M-O-P... and I was under the impression they were from private sets of landlords' apartments, but all I can find are pictures of those late-18th century chips depicting different animals that were drilled and kept on ribbons... of which none had denominations.