Misc photo seeking info on who, when & where?

The picture is with others titled ‘SDC Exhibitions’. Writing on the back says;

Ken Bargrove (London region committee, far left) and Ralph Broadhurst (Colour Museum, second from right) in conversation with visitors to the Society’s stand at the OCCA 32nd Technical Exhibition, held at the Canard International Hotel, London, on 13-15 May 1980.