Welp...back to the drawing board. I could have easily forgotten some little (much-needed) thing. So, I'll re-check everything in the main model. I have 'much' more parts and pieces built into it, 3D gauges, complete gun models, and the like.
Starting to think part of my prob might be two .dds files, I have in the plane's folder, too. Maybe wrong format, so I'll re-do them, and try both with them, and without. Something very simple, is what I'm looking for. So, that's what it looks like in the sim! One of these days...
I really appreciate the help!
Don't think there's anything wrong with my exporter, since it works great on anything else I've made.