Two Photos of a shell I made and you have already seen, I have just used it to showcase the half barrel mirror display.
The end caps are 3/8 poplar and the slats that make up the half barrel are pine. I got the mirror from Pat Catans and it is one of those flexible plastic mirrors. The inside is 6 in tall by 5 inches wide.
I think it will be a good little display for 3d objects but of course time will tell.
DW