Quote Originally Posted by Stan Reid View Post
As best I can find, the first originally Indy 500 driver to compete in a regular Formula One World Championship Grand Prix race was Troy Ruttman who finished 10th in the 1958 French Grand Prix driving a Maserati.
That appears to be correct. Presumably the ride came about from contacts made at the Monza Race of Two worlds in 1957, where he won one of the heats. Surprising really is that others were not signed up. Roger Ward was interested and qualified, but his entry in the USGP the following year was self initiated with a midget car. This was to be Ruttman's only F1 start, he entered the 58 German GP but DNS. Travel times and low contracts probably discouraged many Indy drivers from perusing more F1 races. The talent was there all along.