This machine with Serial Number AE216888 had to be manufactured 1936. The International Sewing Machine Collectors' Society database shows macihines with serial numbers starting with AE20 and AE22 being manufactured in 1936 but no serial numbers are listed with the serial numbers starting with AE21. This leads me to believe that these units were produced in very small small numbers. The unit works just fine and includes a complete set of fittings and accessories.