The commercial pilot/A&P/IA was completing overhaul and restoration of the Stinson. According to the private rated passenger, the pilot decided to take the plane around the pattern for a test flight. The pilot said in his written report that no flight was intended. Both the pilot and the passenger agree that during takeoff ground run, a strong gust hit the plane, raising the right wing. The aircraft departed the runway to the left, the left wing struck the terrain, and the aircraft cartwheeled. The fuselage, both wing spars, and the stabilator were broken. A post-accident inspection revealed evidence that the aircraft had been moved from the accident scene to the rear of a hangar, stripped of all instrumentation, and abandoned. Witnesses and the airport manager reported the accident the following day. The pilot did not report the accident to the NTSB or FAA until contacted by letter. The pilot reported that a 'dust devil' struck the aircraft but the passenger and witnesses reported a strong gust.