Thanks for your suggestions everyone.
I might give the tri-flow a try if I can find it. The penetrant I've been using, fluid film, is some great stuff and I'm surprized it hasn't worked yet. I'll keep trying. It was amazing how it loosened up the bobbin winder. That wouldn't move either. I think it just hasn't been able to get into the spot where it's stuck. You're right...... only a tiny amount of oil would go into that area. There isn't any plastic on this machine anywhere..... it probably predates plastic..... 1899.
I think it's so great that when you have a question all you have to do is ask here on the QB! Someone always comes up with the ideas to try.