I'd want to get the basics right.
Dial colour
Moondisk the right colour, or close enough
Pinions that don't look like omelettes
Proper end links
Functioning power reserve
Correct moondisk movement
Decent lume finishing
I don't need the case to be 100% correct, as long as it's close enough. Recessed crown would be nice, and ideally 8.5mm or thereabouts thickness. Extra bracelet polishing would be a nice bonus too.
Personally, I'm less concerned about the back end of the watch, so full engraving and 22k rotors are not my priority unless I'm going for a high end build. I'm sure others would have different priorities, and that's fine.
And no BMW X5 please. They're frightfully vulgar.