.. My 15K treadle is 1945....and it has the same stitch length knob....My bobbin is like the 15K80 shown above.
Thanks Muv. I think I’m going to have to call it a Singer Centennial 15K80, just from what I can see. I still think that it’s unusual to see all of the earmarks of a 1930s machine on a 1950s machine. The thing that sells it for me as a 1950s machine is the serial number. It doesn’t look to be altered. Several of the other items could be swapped out on an old machine, but surely not the serial number.
If the factory was using up old parts and decals, I’d think that it would be unusual for a machine to get so many 1930 parts on the same frame, when there would surely have been other newer parts lying around to be used up as well, especially the upper tension assembly.
If it’s a “special” machine that someone has put together (outside of the factory) to throw everyone off, they went to a lot of work to make it look “right”.
FWIW - The sample photos of the bobbin cases on my machines are dated as follows:
1913 Singer 15-30
1930 Singer 15K80
1941 Singer 15-88
1935 Singer 15-90
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