Thanks for stopping by and commenting on the build.
Regarding the mask you cut each one out then make minor cuts to it to get it to fit the area you will be masking. Then you do what is called weeding which is to say you remove the shapes from the mask. Finally, you position the mask on the appropriate area and apply it. Once done you are good to go with your airbrush.
I am kind of amazed at how many colours these aircraft will actually have once she is complete. You got your NMF, then Kawaski green, Orange yellow, Red, Black, White, Blue, Propeller brown and of course RLM79. Like Terry said of one my models its looks "Card like" If I understand by what he meant by that than this one definitely looks the part. The weathering will tone it down but thats how Kobayashi's a/c looked for the most part.
I painted the vertical red stripe on the rear fuselage. I originally painted it red but it was too close to the colour of the hinomaru markings and I wanted it look more like the colour on the tail which would give a sense of field applied paint versus factory applied such as the markings. I added a bit of vallejo rust brown to the red for my mixture (same as the tail) and fired away with my airbrush.