Who's This? Silver guy on the lower half of page 4 in Who's Who vol. XXI.
How you could have heard of him: In the post-Crisis DCU, the Silver Ghost only rated a few panels. He appears as a member of the Joker's superhuman army in The Joker's Last Laugh #4 (2001), and as an informant for Black Lightning in 2006's Justice League of America #12.
Example story: Freedom Fighters #1-2 (1976) by Gerry Conway, Martin Pasko, Ric Estrada, Mike Royer, Pablo Marcos and Tex Blaisdell
Who else? Ok, so Silver Ghost wasn't a Quality character, but our next find will definitely have been spawned at another company.