When I was a kid, EVERY arcade, pizza parlor, convenience store, movie theater, or any place that had games for that matter had an Operation Wolf. Even if the store or restaurant only had one game, 9 times out of 10 it was Operation Wolf. Mortal Kombat was always very common too. I remember reading somewhere once that in it's heyday, literally every single arcade, bar, pool hall, etc. had at least one TMNT machine as well, so the production numbers on that had to be very high.