Edit: Here is a pic of the game from the flyer. Has a better pic of panel that u_rebelscum was looking for.
http://www.arcadeflyers.com/?page=flyer&db=videodb&id=1252&image=4
Interesting. The flyer says it "only shoots left or right"; so was that stick a 2-way? Or a 4/8-way that only the left and right were wired? IOW, should it be called a dual 4-way joystick setup, or was it a 4-way + 2-way joystick combo?
And since it shoots only left and right (regardless if the stick was 2, 4 or 8-way), I can easily see an official upgrade kit, or a bootleg kit, or operator hacks with buttons instead of a stick. No need for dipswitches or any hacking the ROMs for it to work. And from what Zebidee and mame, and TOK and NOP say, looks like both ways were out in the wild. (so I was half right in my bet

)
How controls.dat should handle cases like this... well (IMO)... If there was an official three button kit, both are completely correct and control.dats should account for it like it does dipswitch changeable inputs. OTOH, if the 3 button was only on bootleg/hacked cabs, then the 3 buttons should be mentioned in the comments as a side note. There still is the question of if the two joystick setup is dual 4-way controller or a 4-way + 2-way combo CP?
As for Mame, ehh. It's unusual enough for mame to treat it however it wants. (I wonder if there was an arguement about this when tut first was added?)