Obviously but you can do that to the .blend too which is included in the OP. I feel like I'm missing something here..
the OP has it being textured in constructor. you can texture it in blender, export it, and the textures will load into constructor. I don't know about the coords though.
Yes. It is a pink texture. In the screenshot above the interior is clearly not pink. My point is that the null texture is not applied in the game to interiors lacking textures.
Bump and I assume you could do this with any other model.