Just a thought, but what about Time Out (online)? It might not be "on brand" but could spread to a wider market (Time Out is a global "what's on" for tourists and locals) or raise new interest among readers/masses - ultimately supporting this event and planting seeds for any future activities?
Done it, contacted twice. :) and done a few London based events site
Done it, contacted twice. :) and done a few London based events site