[WWI] about weathering

[Diego Fernetti]

The recent Karaya kit of the Nieuport 25 came up with an interesting set of
pictures of the finished model
http://www.karaya.ceti.pl/eng/sf_ni25_2.html
Shows a well worn (more than that, a SOILED airframe, IMHO) Nieuport, and
this made me remind something I've been thinking of...
How does weather a silver painted airplane? Maybe it just becomes duller, a
light grey machine? Or like this, it shows patches of burnt oil and grime in
spots? I've seen several black and white pictures of nieuports in state of
unrepair, especially the Russian machines, and it's a fact that you can tell
apart the newwly covered nieuports and the ones that have flown its share.
But how did they looked like? Modern replicas are too clean and polished,
while the only contemporary colour picture I know of an aluminium doped
Nieuport shows a pristine machine.
Any thoughts on this?
D.