Brad,
This forum topic actually evolved into 2 separate issues: Bettles and NAC, which may be a little confusing.
Bettles issue:
So, to confirm, you have the following in RTMMTwo Object LibraryFSXP3D\textures, and you copied them to the main texture folder, correct?
nac_airfield_shed.dds
nac_airfield_shed_lm.dds
nac_lumber_dgray.dds
nac_roof_ceramic_old.dds
These are the required textures for those buildings. Since they show up nowhere else on your system, I can't figure out what your issue might be. The buildings display fine for me and others. The OP solved his texture problem, but didn't really say what he did. I don't know if he moved them to the main texture folder or not as a fix.
Not being a P3D user, I've read where clearing your cache and reloading can sometime fix some weird display problems, but I can't confirm this myself. Doug has mentioned this numerous times as well. It would be helpful to know what others see at Bettles, so if anyone else can chime in I'd really appreciate it!
NAC scenery issues:
The duplicate textures you list don't include the ones that I listed above, so there can't be any interference. That being said in order to keep from having duplicate textures hanging around in several places, I'll take a look at things and perhaps redo the Part IV library, remove any duplicates, and reissue it in order to eliminate any confusion or issues that might crop up in the future.
I also should add that anyone who had any of the NAC sceneries installed on before I issued the Part IV library, then they would already have had the textures that you listed on their systems anyway. Food for thought.
I'll keep everyone posted on this, and in the meantime, if someone else can confirm the P3D cache thing, or is having the same missing texture issues, I'd appreciate hearing about it here.
Steve