That whole discussion may be mute (moot? what if it's not relevant AND can't talk... muot?), since as I understand it the company that made this game no longer exists. The owner of the machine has attempted to contact the manufacturer several times to order parts, and was informed that the company no longer exists. KLOV (ETA: and your post) lists the game's manufacturer as a Korean company GCTech, which may or may not be correct. The company is defintely Korean, since the owner bought the machine from Korea, but GCTech as currently registered wasn't formed until 2009, and the game is from 2002... and GCTech is a green energy lighting company, not a video game company. I'll know more about it's actual manufacture when I get back to the cab and get a look at any plates it may have.
Either way, he's entitled to a back-up, since he owns the machine... and he's allowing access to the machine to emulate it for preservation... all within his rights as owner of the machine. Quite frankly, how's this any different than the other 7304 sets preserved in MAME? Why draw the exception now?
ETA:
>We are talking about a platform that is not required to be preserved. If the platform had some obscure CPU I would be more understanding.
It's the one and only known cabinet of this now orphaned title... is there anything more obscure than one and only known? Once this singular cabinet's hardware fails... this title may be lost forever. If ever there was an example of why such code should be preserved... here it is.