Duane A. Stewart III » Member Directory Go back to directory. Duane A. Stewart III Buchanan Ingersoll & Rooney, PCPatent, Trademark, Copyright, Trade Secret, Litigation Work One Oxford Centre 301 Grant Street 20th Floor Pittsburgh PA 15219 work Work Phone: 412-562-1622work Work Email: duane.stewart@bipc.comINTERNET Categories: Attorney Updated 4 years ago.