My bad, these louvers are a specific feature of the Jon Shirley Alfa Romeo 8C 2900B (s/n 412035) which won both Pebble Beach and Villa d'Este Concours in the past couple years.
The photo must be taken in 1948, showing then owner Frank Griswold who entered the car and won the Formule Libre race at the SCCA's Watkins Glen Grand Prix