While I was checking my reference for the wood panels orientation I remembered that I saw something in the NASM restoration pictures that catch my attention: all the interior wooden panels were green tinted!
At first I thought at some protective paint given by the U.S. Army before ship to the USA, but at a closer look it is clear to me that is not an overall sprayed paint but a proper coat given to the wood parts, sparing all the metal ones.
I upload a pic for clarity
Here the link to the Museum page:
airandspace.si.edu/collections/ ... ho-229-v3/
To me this is an original protective paint, probably that heat-sensitive paint that in the references is cited as given to the metal parts but it makes much more sense on the wooden parts.