Possible Clues:

• Woo endlessly, embracing with sincerity
• It's the state of being open made tin sour
• Opening up tin, that's hard
• Confident and resourceful, ancient city displays openness
• With positive attitude, you are said to show openness
• Can Frank get like many a 33 down? (7)
• Openness and positive attitude at old settlement
• Jail grim, but with an open quality
• Entering 'The Dog and Duck' with no attempt at concealment
• It's Frank that's able to get like many a Scot