Possible Clues:

• Rely on revision to secure top mark soon
• Before it gets crowded
• When an eager date arrives
• Like king or queen in Bow, head off in good time
• Too quickly
• Greyish at table for breakfast before 7am?
• Noble, perhaps, if it's before time
• Guillotine almost too soon
• By way of being noble in the morning
• Noble, perhaps, before one's time