The pilot reported he was returning to the airfield as part of an eleven-ship formation. The wind at the airfield was 220-230° at 7-8 kts. He landed the tailwheel equipped airplane on the left side of rwy 36 and he kept the tail up during landing rollout to allow for spacing with other aircraft in formation. When he began to lower the tail to the runway wind hit the left side of the airplane and lifted the left wing. Despite the pilot's control inputs the airplane crossed to the right side of the runway and continued into the grass, coming to a stop facing south. The left wingtip, aileron, and outboard aileron hinge struck the ground during the excursion, substantially damaging the airplane.