More interesting pre-war cars.  The Indy Roadsters seem a better fit in this class than with the Formula cars as they actually evolved from 1930s European racers.  Amazingly, today's CART Champ Car formula is a direct descendant of the 1930s Grand Prix regulations.   Images are clickable.
 
 

Peter Giddings -- 1935 Alfa Romeo 35-8C	Mark Gillies' -- ERA
1925 Bugatti T-?? & 1932 Alfa Romeo 8C 2600	Rob Walton -- 1940 Maserati 8CL
Marnix Dellenius & Larry Menser -- Indy Roadsters	Joe Freeman -- 1938 Sparks-Thorne "Little 6"