I don't agree, I think in designing such a fine piece of craft (possibly even in space, where there is no dirt!), you would take much care to keep it clean, and from being weathered.
Now whether it's built on Earth, on some futuristic space station, or a different planet, could affect that totally, as well as where it's been, such as having a heavy battle, by a big, soily, planet, with lasers and rockets flying into it, shooting up dirt to land way out onto one of the ships.

But nevertheless, I think it'll be cleaned up time to time.
Bricks just sit there, on Earth, and nobody ever messes with them again. Depending on their location, they get eroded, some more than others.