Yep I was going to say the exact same thing. The RallyX cab is about 6" Shallower than a Pac-Man or Galaxian, but should share everything else in the profile/mounts. I didnt' say that was an option in your other thread because it's VERY rare to see a RallyX cab, plus your first picture didn't show the side profile fully.
It was shallower since the monitor could be mounted horizontally instead of vertically, saving some space for where the tube would have popped out the back, plus the fact that they often used horizontal frame monitors instead of vertical, causing even more bump out if it had been a pacman mounted vertically.
In fact if you simply change the monitor frame in a Pac/Galaxian you can trim off about 4.5"-5" of depth on the cabinet before you run into the neckboard. Thats a lot of wasted space, but does help for stability.