I just bought this very machine tonight. Mine has only one number on it and it is 20251. Under the base, ther is O W 1 etched in the metal. I was hoping to find the manual but I think that's a long shot. When I bought it from a classified ad it said Centennial so I assumed it was Singer. The man said he bought it for his wife 20 years ago and she used it once and put it away. I would love to know more about this machine other than it was made in Taiwan. Like how to thread it properly! If anyone has any info please share! TY!