I have a Singer 66 made in 1926, and a Singer 99 made in 1925.. I'm trying to find out if there is a sub class on either machine.. The Singer 66 is a forward only machine.. It was converted from treadle.. and it purrs like a kitten.. The Singer is a 99 is in a bent would box.. It also only goes forward.. This one I have the manual for... It was so well taken care of that the pages in manual had pieces of tissue paper in between each page..