Striking Boeing workers turned down the aircraft manufacturer’s improved offer of a 35% pay raise over four years, meaning the strike, which has paralysed the production of the bestselling 737 model and the long-haul jet 777, continues. The vote showed 64% of the rank and file opposed management’s increased offer, the IAM union said in a statement on Wednesday. “Ten years of holding workers back unfortunately cannot be undone quickly or easily, but we will continue to negotiate in good faith until we have made gains that workers feel adequately make up for what the company took from them in th…