AFAIK, P-51D's had their wings painted silver (upper & under surfaces)
before delivery, while the fuselage remained with a natural metal
finish.

OTOH, I've seen some pics of WWII P-51D's with wings in natural metal
finish.

On a scale modelling forum, someone pointed out that "... the covering
on the wing was not very stable and started to peel so they just
removed it and that is why you see so many P-51D's with natural metal
wings".

Does that make any sense? Any other thoughts? Tks.