I jest got home from work, i did check it before i left and your model looked good but half your polys were facing the wrong way. I'll flip them for you and do a light smooth and upload the file. What i meant was finish the model first, nacellas, saucer and wings then smooth it, then UV map then texture it. It was my experience that some times if you smooth a part, then build another part and smooth the hole thing again the original part may not look right.