BigTattoo-there is a better material than CD Jewel Cases,which are fragile,brittle plastic.
Try sheet styrene,or I think in the UK it's called Plasticard.It is sheets of plastic,usually white,that come in a wide range of thicknesses,from 10 thousanths of an inch to am 1/8 of an inch.( metric measurements in the UK,of course

).
It's easy to cut and can be glued with ordinary cement for model airplanes-I use Tamiya brand.
If you don't have a model shop near you,go on the Hannant's website.
