What a great machine!
Unsticking the needle position knob is hard, but do-able. But you can't pry the knob out, because it can break. You have to loosen the insides, then push the post out from the inside. There's a hex-head screw on the right side of the assembly that needs to be loosened. Clean up the old gummy oil, then put it back together. Then you have to be careful with the tracer pin. If you push the tracer pin in, it doesn't like to come back out, so use heat to loosen the spring on the tracer, before you try to work with it. Then dissolve the gummy oil inside the pin.