I took my last piece of solid chrome-moly bar and turned it down from 1.5"to 1" with shoulders at both ends to centre inside the flap bar, then relieved it to accommodate the oxygen cylinder blister and tapered the inside to save weight. I left about 50% greater wall thickess to compensate for the reduced diameter, but the loads on the flap bar are minor and the spacer is only supporting the starboard side. Later I'll TIG weld the spacer in place and repaint.