Welcome Aboard Oran!!!
Nice first post
I like the whole WWII war propaganda poster idea. I think you were on the right track in treating these sensitive pencils with muted colors. I would have liked to have seen an almost watercolor approach to it. You almost got that with the subtle shading on the ghostly cloak over the background.
The overall impression of the image is very strong, and certainly true to the period it evokes. Well Done!