It’s probably a little late now but file this away for next year ..
Photograph the local war memorial the ask pupils to take a name and to discover their story.
This will provide an opportunity to look at massive online databases (such as the war graves commission).
It may also be possible to look at the German perspective (in Google use a search like
“World War 1” + site:de
(this will give you only sites with de (ie Germany) in the domain)
As an aside .. I have a great collection of WW2 posters – Make a comment and I’ll email them to you (or maybe provide a link to download).