Thank you all for your kind comments
If you can keep a secret, (from the wife) i'm going to turn an exact copy of a clay onto wood, then somehow, yet to be decided, mount the first 2 spent cartridges my wife fires with her new shotgun onto it
So far i'm thinking of using 3 spent cartridges, one as a base in the centre of the wooden clay, then the first 2 she fired suspended on some thin wire to give the illusion of being ejected. Ideas are still zipping around in my head. I know she'll love it.