In fact one of the founders Roy Farrell was an American.
The bulk of the drivers in the late 50's and then 60's were Aussies augmented by Brits/Irish and then some Americans from Bahamas Airways. Jim Lovegrove, Roger Stuart and the late Charlie McGowan were very pleasant addions to the gene pool and all served out their time in CX.
CX has never been a restrictive gene pool.