Not as sexy as a complete shell, but I also like ones that show off how these things worked/were made as well.
This is a 3in Selma Broun shell with a segmented interior. I believe this cutaway piece is the one shown in the books by Melton and Pawl. Next to it is the base of a 10pdr CS Read/Parrott. It has a very offcenter cavity, a dimple in the middle of the base, and the 3 lands and groove rifling from a Parrott rifle.
