Possible Clues:

• What does father make of the RAF?
• A horse and an animal in 11 across is just a matter of letters
• Word created from other word
• Rearrangement of letters in a word
• 'An Indian city' - first of many a type of clue
• 17-Across or 11- or 29-Down, to 61-Across
• Altered word in a puzzle?
• Twist of phrase, perhaps
• Schoolmaster, to the classroom
• Just a matter of letters for a horse and sheep