What is the purpose of the small square rubber dot / pad on the apron? This is on a Data East Lethal Weapon 3 machine. It is just in front of the Data East logo. Is it meant to be a sort of padding in case someone leans hard enough on the glass and it takes the weight onto the apron / playfield? Mine is sticky, that's why I ask. Feels like there's adhesive on it. Probably just the rubber deteriorating over time though.