Richard Rust as Gus Steals the Show
He even inspired part of a short story.
http://www.angelfire.com/jazz/stump/html/dsatdb2.html
scroll down to The Shades of Richard Rust.
Anyway, Rust was 15 years younger than Robertson (who looked AWFUL in this movie) and it showed. Rust looked handsome, wore nice suits and stole scenes by turning a zippo, eating a banana and smoking. Whenever he was ordered to hit, his eyes glazed over, he put on his shades and went to work. A great characterization, and he should have rec'd much more attention because of it! An amazing performance directed by Sam Fuller.
my richard rust photo site:
http://richardrust.multiply.com/