During editing, he scratched some of the film with steel wool and dragged it around a parking lot to make it appear neglected by wayward projectionists.
The ceiling above the main lobby is notable because it was handpainted to look like wood (steel wool was used to fashion a wood grain in the plaster before painting).
Steel wool can be treated with vinegar to create an acid oxide, then brushed across a stripped and sanded surface of the piece to create a vintage stain effect.