Finally finished my YLQ and am happy with the results ! This particular Yale has a steel lower vent and brass top vent , steel collar and steel fount ! It bears the single patent mark on the air tube but no other markings other than on the diamond shaped top nut . Runs real nice too!! These apparently had an optional ML99 generator that allowed them to run on kero ?? Found in Indiana
Thanks all ! Yes nearly passed this one over as an AirO in the pics when I was looking at it as the finial was side on and didn't notice it !