I'm guessing it may be a 17-28 which would be fun for me. Although since I got my Singer stocking darner and tried it out on a 301 that seemed to work pretty well. I'm basing that on
http://www.sil.si.edu/DigitalCollect...es/image54.htm I
think there is a parts list here
http://parts.singerco.com/IPpartCharts/17-1_30.pdf (too large file on dial-up) I couldn't find an instruction manual.
From the image at sil.si.edu it looks like the bobbin winder may swing up from the pillar.
I hope you checked it out, and/or got more pictures. Would be fun to see.
Janey - Neat people never make the exciting discoveries I do.