The battle wages on. The Singer 403 I was a bit less than accurate about. I called it a sewing machine, but at this point it's risen from boat anchor, to doorstop, to lamp. It's now fairly clean and the light works! I am making headway very slowly I saw just a bit of movement down the main shaft closer to the front of the machine. More oil, more heat, more patience. As long as I don't get in a hurry and wrench on it too hard, I may just get it running yet!