Simply copy the items from your cached list to a new list. The instances will be the same but the original (cached) list will not be touched. Something like this.
What Malcolm Frexner is saying is a nice clean way to solve your problem but can be greatly simplified using AutoMapper.
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.