I need to source a couple of stainless steel offcuts and wonder if anyone knows where to try? I need a 200mm length of 100 x 100 square hollow section with a 3mm wall (or close to these dimensions). Also a 5 or 6mm plate to weld over or into 1 end. For a boat and to be welded so 316L I understand will be correct grade. Look forward to advice. Mike