You're welcome Jonathan. I love detective work! I should really get a job in research in the future. I have to admit, that image search didn't take me straight to it, it was a few pages of exact copies of that image before I found the blog with a credit, and then a search of 'Mary Quant' on Getty came up with 4 pages in chronological order - apparently they do tag the images with keywords! There are some quite groovy photos of Mary Quant products I've never seen before on there too.
I do like the image search function for cutting out the rubbish Google can spew at you, and it is getting better over time. I often forget to use this method though!