You were just a kid! You obviously have great remorse, and would never do it now that you know what it is! Trust me, I don't think you've done anyone any damage, since it sounds like everyone was too young to even know what was going on... just like you.
I would try your best to move on with your life, and just be the best person you can be from hereon out. :).
I guess if you don't see any signs of him remembering then you should just move on and wait and see if he brings it up or acts weird in a way that you know that he has remembered what happened. If you then discuss it keep it between yourselves to avoid judgement from other people.
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.