Note that only late 9W7's came with the flat bobbins. 9W1's as well as early 9W7's still used the same bagel bobbin as the W&W D-9.?
9W1 machines still wore W&W decals & fit W&W cabinets. These were made from 1905 to around 1908. The 9W7 was introduced in 1908? was made through 1913. The bed on these was modified to fit Singer cabinetry & they wore Singer decals. I do not know exactly at what point the bobbin change was made but likely only the last couple of ears of production.
