Sorry for the late reply.
I found some of WWII planes folded from other origamists but I don't think there are any crease patterns or diagrams existing to help you

.Maybe crease pattern of Zero Fighter of Kamiya's design would be helpful? I can send you the cp if you want. One of my friend have designed a origami WWII plane and posted on his blog(
http://blog.naver.com/jiho0910). Maybe you can see and get some inspirations on designing?
Also, I have designed some planes some years ago and something that can be useful and easy to use was a traditional plane. You just have to give some pleating-grafting to have the detail and give some blintzing to change the ratios of the parts(at least this was the easiest way for me

)