The Cherry Picker(1974)

American V.I.P James Burn II finds his son James Burn III (Bob Sherman) leading a giant "sleep-in" that has taken over Windsor Castle. He hires Nancy (Lulu) to get him out of the castle and into work. With the help of her crazy eccentric father, (Wilfred Hyde-White) who believes in working day and night and producing nothing and uses a fantastic astro-telescope for casual bird watching, she does just that !