Dating singer industrial sewing machines
If you see lots and lots of listings for your type of machine, it probably means that there were many manufactured and there is not a huge demand.
Or, you may have a hard time finding a machine like yours it could mean there aren't a lot out there - in which case you might consider contacting a professional appraiser for help.
Keep this information safe in a folder or envelope, and keep it updated as much as you can..
The Fair = A machine that has definitely been used, possibly not kept up as well as others.
Usual wear and tear for a well used machine, pin scratches, some dings in finish, some rubbing off of decals, but machine should work.
Some accessories missing or in non-working order, manual may be damaged or missing.
Poor = A machine that has been used hard or has weathered badly.