Jay
Familiar picture often used in reference books, Hard to put exact date on this picture, but looking closely at better quality print all the Aces have flat screens and drum brakes, whilst the Aceca has square lower corners to the windscreen, Assuming all the cars are New and ready for delivery I would date the picture between 1956 and pre August 1957. This is only a guide, let the experts like Rinsey Mills and those who worked at AC at the time, home in on a more accurate date.
Keith