I might be mildly ambivalent about receiving my MIL's engagement ring; on the one hand Charles and Diana were not a happy couple. On the other hand; William gave a ring that is deeply meaningful to him; it could be viewed as a piece of his heart, and so I'd be inclined to accept it as something very special. Kate and William can choose wedding rings that are especially theirs; reflecting their style, tastes, and their own relationship.
I'm with you Lily. There is no love bound up in that particular ring. I would be worried it would act more as a lightening rod for ill luck!
The better idea would have been to get Kate her own ring, to her personal taste, and then use his Mum's engagement ring to make a different gift for the bride--maybe made into a necklace to be the "something blue" most brides like to wear on their wedding days? (The central sapphire could stay the same, with the diamond surround worked into a heart shape instead of the oval it currently is.).
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.