yeah thats the tricky part, Midway used the same basic cab for 2 and 4 player games (NBA Jam, NHL Open Ice, Killer Instinct, Mortal Kombat,etc) and even the same coin door, just with an extra set of mechs )hence the wider door. I think Konami did the same thing, used identical cabs for 2 and 4 player but instead of cutting out 2 holes for 2 sets of coin doors they just cut one in the middle.
all the pix I fond of Martial champion dedicated cabs look just like your cab, so its my best guess it was a martian champion. the only other US released konami game in the US in 1993 was Gaiapolis and it was a vertical game.