I have bought a house with an older White Westinghouse Convection oven Model#WFS81TW-1. It is self cleaning but does not have the padlock symbol on it. It does have a kind of starburst symbol on it though where I would think the padlock goes. Would this be the self cleaner? I would like to clean it and know how to use it, is there still a manual available for this range. Thank-you.