Originally Posted by
Mickey2
...
To make it a bit more difficult, Singer used different subnumbers for hand crank, motor and treadle, this can turn up as a third subnumber, like 66-10-1. I think the last one indiciates motor, treadle or hand crank.
Do you have a source or link for that? The Smithsonian has quite a few Singer catalogs online. I pointed to a couple about "Class" and what they called "Variety" on the thread
Singer 66 sewing machine It seems the modern terminology refers to them model and sub-model numbers.
Janey - Neat people never make the exciting discoveries I do.