Foil balloons will remain buoyant for about 2 weeks. They stay firm for the first 2-3 days and after may need slight re-inflation for firmness (not buoyancy), which can be done carefully with a straw and air. More.
Latex balloons have a limited life of about 18-24 hours for 11-12" pearlshine (metallic) balloons, so inflation should be done as close to the event time as possible. We are able to supply a product which can increase the float life of a helium inflated latex balloon. 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.