It is not a gun calibration tool It's a compass. It swings it around with zero distance.
The only stuff repainted on the captured models is the national markings covering up the crosses, and the hand-painted reference numbers on the tail.
I do think the cross/swastika on the second pic are photoshopped in for some reason. Those would have been painted over (like the first picture).
As for weathering... Even if you left it out in the snow and rain for 2 months straight it wouldn't look heavily weathered... It would look dusty, like how rain/snow leaves dust behind when it's gone, but an active in-flight unit would keep the planes in hangars or covered, and rinse most of that of with general maintanence. Look at the highly polished underside of the wing in the second captured pic. That's end-of-war, been through the worst, and they still kept it clean enough to catch the light.
I think they're good examples. Not definite, but give a good idea, and are appropriate to the time frame in question.
EDIT: Conversely, let's see some of these examples where "every photo I've seen is beat to hell" -- I've only seen a couple sitting around 50 years after the fact that look totally wasted.