I'm really impressed by this, been looking at the models closely, and from the textures it looks like it would be 20 or 30k in faces, I was surprised that the exterior is under 10k
I did find a few issues with the models though, I hope you don't mind me pointing them out
At first I tried opening each model with Jeremy's XWA Opt Editor, but each model crashed the editor, I manage to import them into optech but the reason for the editor crashes, was that on each model there is either one or two textures with the incorrect texture dimensions, I'm not sure if this will effect the game or not, but it might be an idea to correct these texture, plus there are a few other issues which are easily fixed, I'll go through each opt
First the Exterior Opt
Tex00007.bmp the texture dimensions are 512x312, it needs to be resizes to either 512x512 or 512x256
There are faces that need to be deleted as when you click error check a list of error shows "Face normal does not correspond to orientation of face." these all called coincedent vertices they show on the model as a line and if deleted won't show any visible difference (again not I'm sure if they might cause the game to crash) but I would recommend they be deleted.
Faces to delete
MESH 6, Faces 37 to 68
MESH 34, faces 5 and 6
MESH 35, faces 51 and 52, 79 and 80
Base Opt
Tex00001.bmp the texture dimensions are 512x312, it needs to be resizes to either 512x512 or 512x256
Tex00001.bmp the texture dimensions are 296x512, it needs to be resizes to either 512x512 or 256x512
No faces to delete
LOD model
You've added a LOD model to the base, but it will never show in game as you haven't set the cloaking distance for each high level mesh, at the moment each mesh it set to 1000, this mean the high level model will always be on screen, to fix this set each mesh to something between 0.4 to 0.6.
Cockpit Opt
Tex00005.bmp the texture dimensions are 512x312, it needs to be resizes to either 512x512 or 512x256
Faces to delete
MESH 6, Faces 26 to 36, 42 and 43, 74 and 75, 113 to 118, 121 to 124, 130 and 131, 162 and 163, 203 and 204
MESH 17, faces 101 to 104
And on R2's shoulders, a number of faces are inverted Mesh 5 faces 47 to 128
Apart from them few issues it's a really great looking model, and the textures are brilliant, love the cockpit