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I'm not sure FSDS has a way to create a root node. Maybe it does and I've never noticed it. FSDS models done with XtoMDL do not have this problem.

A "root node" is merely a small part, (in FSDS you can even tag it as a hierarchy part so that no geometry is exported), to which all other parts are linked.
Sidebar:
FOr aircraft models, you do not need to create a 'root node' because FSDS's model pages basically are a root node. THe "main model" is the exterior root node, and the VC model page is teh "interior" root node.
But, do these "model page" have axis properties?

I want to think that there may be a texture issue in the Kletten's building model. I believe that this issue has come up before. I'll continue to look into it.

The 172 paint scheme looks like it's from FS9, so I'm assuming that we're not talking about FSX.