Racing car no 6 from 1950s motor race meeting

A picture from a motor race meeting in the 1950s showing a racing car with number 6 written on the door. This was presumably moving at quite a high speed, but the photographer has managed to capture it quite well with a reasonable amount of detail (apart from the fact that this old picture is a bit blurry anyway!).

I'm not an expert on cars, or in fact even particularly interested in them, so I'm hoping someone can recognise this car and from it possibly the driver and the likely location of the race meeting.