P.V.C. sphere
P.V.C. sheet, here 0.6mm thick, can be readily vacuum formed into hemispheres.
The two halves of object 5 were used as formers, once for the black base, and then once for the clear "lid" with the addition of a leaf placed betwen the former and the p.v.c..
The base has a rim slightly larger than the lid to facilitate a close and accurate fit. See object 24.