Ok, I'll try to explain this as simple as possible so you can understand what I wrote.
Enioch asked:
But, just out of curiosity, how do I go about texturing a model from scratch and retaining that freespace feel?
I replied:
Texture it freespace-y 
If you watch carefully, most of FS's textures aren't clean, on the contrary, they are full of grit and stuff, that's what you gotta simulate.
blah blah blah
Notice the bolds. We're talking about Freespace craft, not real craft...
But since you brought it up, and I'm not claiming I'm a material\aviation expert like you obviously... I take it that you've seen those grey-black carbon materials after prolongued exposure in stress situations, like the ones you get in a military theater.
I actually already had a rough idea how military planes are built and how they are plated, same goes for a space shuttle, and boats... however I believe you're missing some points:
- in Freespace ships are made to be used in space only. It makes sense in a plane or the space shuttle that the plating is only some cm thick (which makes for very small, if any, visible seam lines), since they need to fly in the air and as such have to be light enough. However in space-only flight you aren't bound to make compromises with weight (except when it comes to inertia, and accel\decel forces), and as such the plating can be much thicker=more resilient. That way I'm pretty sure that seam lines would be more visible.
- Freespace is an entertainement product. As such, although we do however should transpire a certain level of realism on the ships, we don't have to do it full real (which makes sense, since there aren't any real spaceships)... coolness, shape "reading", and sticking with the FS universe is however needed.
It's all fine and I respect it if you want to make ships that resemble what future spaceships would be like and pretend they would work. However, that wouldn't be Freespace-y.