Possible Clues:

• Electricity generator in Post Office nicked by subversive group
• Power source something a tourist may take to flog, we hear
• Electricity generator nicked in post office — thief may end up here!
• Brightness detector
• Still room for current producer
• Page 100 in 'Othello' amended for the current producer
• Producer of current picture linked to subversive group
• Device used to detect and measure light and other radiations