I'm sure that shot was on the AGSOB site at one time and it was described as late 1940's. Can't find it now though. Think it's Lister Street in the background, Gordon. Certainly, the uniform regulations seem to have been abandoned - maybe they had special dispensation because of rationing etc.
During my time at the school, Ben enforced uniform rules with an iron hand...except towards the end of his regime, when he seemed to get a bit demob happy. There's one full school picture from April 1967, just before he retired, where I'm proud to say I'm not wearing one single item of school uniform!
