Who are the people from the grey waiting room?

Grey person one (Eye-worms, p 18) wax model
Grey person one (Eye-worms, p 18) pewter
Grey person two (Eye-worms, p 18) plaster model
A marble sculpture of a human figure with a human skull resting on its shoulder, photographed against a dark background with stars.
Close-up of a modern sculpture of two faces leaning against each other, with one face having a prominent crack running down the center, set against a dark background.