Both my Walmart and Joann's had the singer oil, but neither had the motor/gear grease. I did find it at the singer shop. You can try the liquid wrench or wd40 on the screw, the wrap it in a cloth and due pliers. I would get a new screw to replace it with. As you can see, the screws don't need to be super tight, just snug enough to hold their part in place.