Lovely job.
I've made a couple of hangers for people.( so you can sell them however you'd need to simplify the build otherwise you'll get nowhere near the man hours you've put in.)
Your solution to the hanger door's is elegant and simple. I spent hours constructing rolling hanger door. Why? because it never occurred to me. To do it this way!

So hat's off.
On the plane.again very elegant and simple solution. Using card for plane's is one of my favourite ways to use cereal packet card.
I'd recommend going back to the plane and changing the colour of the windows. As these details are lost within the colour scheme. The blue of the fuselage camouflages the window details. With low texture builds such as card plane's it's really useful to make the details that exists pop .
Such a simple change will lift your model. In fact if you add just a little false shading around the joints of the wings to the fuselage.Along with a multi tone technique on the windows. People don't even notice it's a card build.