The addon to the secondary hull on the studio model is a lot more curved than what you've done. It still looks alright, but I'd pronounce the concave curvatures of the secondary hull addon more to match the studio model as it looks a little too much like a 'glue & gum' addon here. Just a thought. I found some VERY good references earlier, I might dig them up if you need them. Otherwise that's just my two cents. Good model otherwise.