Possible Clues:

• Playwright is very nearly cross
• Mary of Peter, Paul and Mary
• Mary who sang with Peter and Paul
• Ben ____ was the main writer of the 1920s and 1930s Aldwych farces
• Ben --, author of the farce 'Rookery Nook'
• 'Rookery Nook', a farce by playwright Ben --, based on his own novel
• Mary of Peter, Paul, and Mary
• Ben --, British playwright noted for his farces
• Cross, having forgotten inferior English playwright
• Playwright gets a certain amount of material from gypsies