As far as I remember from using Colorbox, it only recognizes images, that have the cboxElement-class attached. Since you seem to already have a function, which changes the big image's source, how about removing the class cboxElement from the clicked thumbnail, and attaching it to the other two images? Might be worth giving it a try.
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.