Adding extra disc holders/spacers inside a Steelbook

[yeslek]

I want to add a holder inside steelbooks for extra discs ie add the flipper middle bit you get inside Pinocchio/Snow White or to add a holder bit to the inside front cover if there isnt one already there

I'm not very good at describing what I want but a steel book that looks likes this

can have bits added so they can hold disc's like these