I found a diagram at Yahoo Vintage Singers Group and took off part of the bobbin race, cleaned it, and put it back. Also a drop of oil. Ahh, now it's working.
Up until now I haven't plugged the 301 in--there was no point since it was stuck. It's time. I give it a try and it's working!--and sounds nice and quiet. But does it sew? Sure the tension is broken, but I have to know if it will form a stitch. I threaded it up and stuck some fabric under the foot. I pushed the tension spring to push the discs together and held them with my left hand. I know, not very technical. But look:
Stitches! And those are the from the underneath side --the top was even better. I expected loops. The feed dog teeth left an imprint in the fabric--no problem. I just turn the screw on top of the presser bar to loosen the pressure and that's fixed.
Next I'll have to tackle fixing the dreaded tension knob.