Funnel #4 wasn't mainly for decoration. It ventilated a quite a few places (Kitchen, smoking room, fireplace galley and turbine engine room) and served to replace many vents on the Deck (compare with Cunard's Lusitania and Mauritania)
Amazing job on the model! Only critic I have about it would just have to namely be the funnel color... White Star Lines funnel "buff" was more of a peachy sand color... If you look up "White Star Line Buff" you'll see what I mean! But other than that minor complaint, amazing job!
The flight deck shield is epic. The model is beautiful.. just one suggestion.. when using neutral colors like these, part color separation makes an enormous difference for catching the eye. I do it with all my models. Ill scribe new panels into a part, then separate the panels by color. A rule i follow for two-toning is you always want one neutral color and one vibrant color at the least. The panel and color separation makes the model look more like a constructed machine and less like a piece of plastic. So for the navy thing i would have maybe done like a gunmetal, and for the smaller panels ive made id do like a light gull grey. Try it next build youll be amazed with the result. Keep up the good work!!!!! Edit: you definitely inspired me to buy another red comet and make a badass USN version.. Army, Marine Corps, and Air Force.. im gonna do a whole iron man 2 line up.. Thanks Much!!