The NI WUMPH may not use the -12v or something.  So if this is missing NIWUMPH would work and original wouldn't?

CORRECT!! the -12v rail is not used at all on the Ni Wumpf board.. it doesnt care if the -12v is there or not as it just floats in the breeze (-12v pin on the board goes nowhere).

I spent over 10x hours earlier this year trying to fix a battery acid damaged System 1 board before giving up (My first attempt at repairing a Sys1 game)

Got a pascal cpu board & all problems solved. In future I'll be grabbing a new $250 pascal board everytime instead of wasting any more time.

Good to know you finally have your game up and running properly  I havent tried a Pascal board as yet but i'm keen to do so one day  My Roller Disco and Buck Rogers still have the original boards in there going well.

My Solar Ride has a Ni wumpf in it, i dont really like them that much as i have had resetting, and switch bounce issues with it in Solar Ride that never happened with an original board.