James,
The party in the bread advert, was to celebrate the 2nd world war victory, either VE Day (Victory in Europe 8th May 1945) or VJ (Victory in Japan August 45). On both days there were street parties throughout UK
I was in the school system from 1945 until 1956. I remember one Greek boy in primary school and one dark skinned boy in an upper year in senior school. I lived in Brixton.
