Pitmaster Clyde Biggins of Clyde’s Rolling Bar-B-Que. (Photo ©Chris Wilkins/Texas BBQ Posse) At Clyde’s Rolling Bar-B-Que — a trailer on Westmoreland Road in West Dallas open two days a week and soon to be three — there’s as much nostalgia on the menu as smoked meat. “Is that Clyde?” an elderly man said as he stopped his big pickup truck beside Clyde Biggins’ barbecue pit last Saturday afternoon. “It’s Clyde,” Clyde said. “Do you know me?” the man in the pickup said. They talked for several minutes, recalling when, two decades ago, Clyde ran a popular barbecue joint a couple…