The gear mold has lots of different sizes and types. Factory worker Tony Cogges (Foundry figure?) sees potential for these for large mechanical machination projects. And if you filed the teeth off they’d make interesting vehicle wheels.
On some of the gears I glued on strips of card, round labels and paper reinforcements for detail.
Painting gear spokes goes fast with a piece of chenille or pipe cleaner.
Prepainted grommets were added by very carefully drilling out the centers of the brittle plaster gear by holding the drill bit by hand. Here are some finished gears. And they all mesh with each other!
Here is the grate mold. Again, lots of variety.