Highlights at Roundhay Park, Leeds, include a rare Rolex 'double red' Sea-Dweller watch and a gold handbag that was left in a safety deposit box by an anonymous benefactor. Marc Allum is excited to see an album of rare and valuable photos of an Antarctic expedition that had been gathering dust in a Leeds library, while militaria expert Bill Harriman wonders at the intricate detail in a Second World War spy radio transmitter that would have been dropped behind enemy lines for use by undercover agents