I know, I also prefer it original.
And if I would mame it, I would always keep the original pcb and wiring harnas. And no spinner, trackball and 88 player joystick setup.
I would give it a 7.5 out of 10, it looks pretty decent, original sideart, good tmolding, and the monitor has no burn. I tried to sell it here for 6 months, but no interest whatsoever. (No, no high price)
So I was thinking, if nobody wants it, maybe I can convert it, so it is at least fun for me when playing a game.
Edit, maybe even install a nes with zapper? Is something like that possible? Duckhunt

BTW I'm in Spain, you can't easily swap this with another machine, because there aren't any left.
Again, I want to keep it original, so I would like to keep all the original parts, but I wouldn't mind more shooting games.