I worked in the labs of Ferguson's/British Radio Corporation from 1965 to 1970. Happy Days! I wonder if the day the picture was taken was one of the many when, if there was to be a "Bridge" (bridge opening) around lunchtime, the bridge operators used to phone us up, to let us know, so that those of us who lived on the east side of the bridge, and went home for lunch, could adjust our lunch hour accordingly? How lovely and quaint. I imagine others must have such memories?