The front seat pilot reported that he flew a stable approach with the airplane configured with one notch of wing flaps for landing on runway 18 at the destination airport. He applied control input to compensate for a crosswind, and the airplane touched down on the left main landing gear wheel followed by the right main landing gear wheel and tailwheel. During the landing rollout and at an airplane speed of about 15-18 mph, a gust of wind swung the airplane’s tail to the right. The pilot reacted but quickly ran out of rudder authority and the airplane ground looped. The right main landing gear collapsed, and the airplane right wing impacted the runway resulting in substantial damage to the right wing and right aileron. The pilot reported that there were no mechanical malfunction/failures with the airplane that would have precluded normal operation. The pilot stated that while standing on the runway, the winds were gusting from 120o.