On February 3, 2001, about 0845 hours mountain standard time, a Luscombe 8F, N747MP, sustained substantial damage when it nosed over during the landing roll at the municipal airport at Tombstone, Arizona. The owner was operating the airplane under the provisions of 14 CFR Part 91. The pilot manipulating the controls was believed to hold a Canadian pilot's certificate. He and the Airline Transport Pilot pilot/owner sustained minor injuries. The personal flight departed Marana Northwest Regional Airpark, Marana, Arizona, about 0750. Visual meteorological conditions prevailed. No flight plan had been filed. The owner stated he knew the pilot was a Canadian military pilot. He assumed the pilot held a civilian Canadian certificate, but did not know what type. The pilot had flown the airplane when the owner bought the airplane several years ago, and the owner let him fly it during yearly visits. The owner was sitting in the right seat and was letting his friend fly the airplane from the left seat. The airplane is not equipped with brakes on the right side. During the landing roll, the airplane began to veer to the left edge of the runway. The owner estimated the speed was about 25 miles per hour. He attempted to help steer the airplane back to the centerline. The pilot applied pressure to the right brake and the airplane nosed over.