Possible Clues:

• Fish
• It's a bit fishy to be fifty in a straw hat
• Fish served regularly in Balmoral to the queen
• Fish left in hat
• Put a pound in the hat for food
• Herring salted and smoked
• Breakfast possibly left in hat
• Partially dried herring
• Somebody maybe taking a punt eating tail of foul fish
• Oarsman catches lake fish that's smoked