So being a Revolution X fan, when I happened upon some info that Mortal Kombat II had a Revolution X ad (with an earlier logo design), I set out to try to see it in MAME.
However, my pointer finger is getting tired of holding down the 'Insert' key to the point that I'm assuming that the ad is not part of the stock attract mode. I did read in the history.dat that the ad was only added in Version 3.1 (which is the parent set and the set I've been running). What do you have to do to trigger it? Is it post-credits?