Hi, I hope you don't mind a little advice 1. Your model is high on verts but isn't high poly, the are 4,000 double verts 2.The are 100,000 verts in the machine gun bullets most of which you can't see. 3. Models are much easier to edit if you separate major parts into separate objects such as wings, wheels, guns etc and name them 4.Try using the edge split modifier on smoothed objects this will get rid of some the strange shading effects. Hope this was helpful!