Great find! Yes you can use some gun cleaner just be careful not to get it on the paint. Just a squirt and let it sit. Once everything breaks free your machine will sew very fast; not industrial fast but she can chew through fabric with the best of the home machines! One area that needs a drop of oil on these old girls is right in the middle of the bobbin case. There is no hole just metal. Go ahead an put a drop on it and let it soak in. Every 400 and 500 series machine I have had squealed or didn't run just perfect, once I oiled the bobbin case - problem solved. You'll love it once you get her loosened up!