Too late, you already altered the past by befriending him and telling him time travel is possible, so at this point it wouldn't really matter that much. There is also a possibility of passing him some microbes to which people were not immune 200 years ago and he dies. I'd show him the notes of any song made by Lil Wayne, just for a laugh (a single sheet of toilet paper would be enough).
I wouldn't give it to him because in all the movies I've seen stuff like that f***ks the space time continuum and alters the future and people disappear and it's crazy.
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.