Hi...this is a suggestion off of the top of my head and may require more
effort than you really want to expend...but, if you have any idea of the
age of this machine, you might try browsing old Sears and Roebuck catalogs
My grandmother has a few and they are pretty informative with good line
drawings.  Otherwise, I would have to suggest looking up antiques in the
library catalog.  Hope this helps.  Those old sewing machines are so neat,
my mother has an antique Singer and it is really cool.  Have a good one.
 
     Tammy