The race is on for the best bargains to be had at the antiques fair at Epsom Downs Racecourse. Among the items found are a Pelham Puppet and an ornate golden clock, and experts Kate Bliss and Thomas Plant are on hand to give their advice. Presenter Tim Wonnacott visits Petworth House in West Sussex and looks at the magnificent staircase, rebuilt in the 18th century and surrounded by vast murals, decorated by French artist Louis Laguerre.