ok. Got the clutch knob off- the trick of pressing on the back of the screw did it. The whole joint was frozen with oil. It looks like motor oil rather than sewing machine oil, but who knows. This is a 1919 red eye. I will take a knob off a donor machine- I just got one out to take a tension spring off... since sew-classic did't have any tension springs for the tension assembly.
thanks guys. A little girl is going to be so happy.