1972 Thunder Jet at the Pennsylvania State Championships in Honesdale, Pa, 1972. That is a 440 model, which ran in MOD III in USSA Eastern Division.
73 Thunder Jet with number 1289 on it was taken in Feb. 1973 at Boonville, NY, New York State Championships, I do not know the driver's name. It is a 292 MOD 1 in USSA competition.
The photos below are from the 1972 PA State Championships in Honesdale, PA, USSA Eastern Division. The 71 Blizzard with the mechanic's rags in the carbs is a 797 cc model.
Here's a photo of Mike Trapp, in his first year as a Ski Doo factory driver. He posed for George at the New York State Championships at Boonville, NY in Feb. 1973. According to George, "Mike Trapp was great. He was headed to the Ski Doo trailer and I stopped him. I wanted an autograph but the ink in my pen froze solid."