A Pacer or even a Maule M4 was one of my thoughts but it does appear significantly different - back of the right hand rear window appears to curve similar to a Cub's (left side is hidden by strut), rear of middle window appears to lean forward, fin is squatter - though granted it may have been remodelled by the inversion! Pretty sure that is an "N" strut and presumably James Gilbert and Mike Jerram had a better quality pic to squint at, rather than off-set litho grey scale patterns!
Apparently it was circling a skiing world championship giant slalom race when the engine failed, possibly carb icing?