Actually, it could also be what is considered a 15-clone. Since it is a modified machine it could have parts that were not original machine. It seems I remember a company that modified Singer 15s and 15 clones to be a dedicated ruffler. I would probably double check the bobbin to make sure it is a 15 class. It seems like I read that some machines that were modified to take a "M" bobbin so that it would hold more thread. It sure looks like a 15 class as the "M" bobbins are larger. For some measurements to be sure there is this link -
https://www.sewingpartsonline.com/bl...y-sewist-know/
I'm fairly certain that the manual I linked to should work. There may be another thread guide before it gets to the nose.
Have fun with your "new" machine.
Janey - Neat people never make the exciting discoveries I do.
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