With the ages you mentioned, you must be working with a Boy Scout troop and a Cub Scout pack. They might not be able to do a service project together. , Check with the local council to see if that can happen.
If you have a local park, they can clean the area and repaint any benches. Find out from the schools that your Scouts attend who takes care of raising the U.S. flag in the morning. They could take care of it and maybe complete some advancement requirements at the same time.
More.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.