Does anyone have routine maintenance information (e.g. user or service manuals) for the Wright Line manual punches? My newly acquired unit seems to need a little lubrication. I'll guess if I have to, but... This is the variety with the large grey wheel on the side to select the desired character, and a sort of "wheelhouse" in the middle to hide the cams, ribbon mechanism, etc. There's no model number sticker on it. Thanks! De