ANTIQUES ROADSHOW rides into Dallas, Texas, where everything is larger than life, including a few examples from a collection of more than 600 antique American flags. Appraisers at the Dallas Convention Center flag down another jaw-dropping piece of artwork: an 1847 oil painting by noted 19th-century artist James Henry Beard, titled The Illustrious Guest - featuring the famous American statesman Henry Clay as a guest in a tavern - valued at $300,000 to $500,000.