I found the perfect duct replacement (from blower motor to right kick panel) for my 1957 Selectaire conditioner. Item #191215111596 in e-bay or contact Ron Schales, 868 N. Fox Hill Rd, Flagstaff, AZ 86004. It is a 6" x 16' flexible duct which can be easily squared off for the top end using your original square clamp. One the bottom end you can use one of the two round clamps which are included with the duct.
