In addition to what bkay said, I would advise
not trying to clean it. Those decals look to be in pretty good shape and
could be ruined if the proper techniques are not used. I think that the bobbin winder is missing some parts and probably need to be made.
A thread I like about "worth" is
"How Much Is My Machine Worth?" Question Answered
Janey - Neat people never make the exciting discoveries I do.