| If you're competing in a scale competition, there are grades | given for accuracy of markings on the plane.
Indeed. Isn't the usual method of operation for a serious scale competition to take a _specific_ plane at a specific point in time and duplicate it was carefully as possible?
i.e. you aren't just making a P-38 model, you're making a model of this one P-38 that was flown by Jack Knoph from this year to this year, crash landed in this year but repaired, so we're making a model of the pre-repair verison?
Usually one picks a plane where there's lots of pictures and such of it (and you do need the pictures for your paperwork for the contest anyways), and so if the original plane has a sticker, you add that sticker too if you want to score well. Seems simple enough.
I don't do scale competitions -- I'm more of a `poke holes in the sky' sort of guy -- but from what I've seen, that seems to be the plan for the people who are really into it.