Picture this scrolling hundreds of feet above the iconic confluence of Pittsburgh's three rivers: "Chipped ham, $1.39 a pound." That's the plot Mayor Bill Peduto says his administration has foiled as it negotiates a new permit with Lamar Advertising for the company's famous 32-foot-tall, 225-foot-long neon sign on Mount Washington, which has loomed over the Point since around the time of the 1929 stock market crash that triggered the Great Depression.