Possible Clues:

• See 50-Across
• Saying nothing is kept up over period of religious observance
• Omitting of mention, in contract-ese
• Like all pre-1927 movies
• Mum let sin get out of control
• Like three of the letters of 'aisle'
• Mum is upset ahead of religious period
• Like early 10s, one's rising fast
• With 63 Across, source of quote
• Not making any noise