It does make me wonder though, what type of oil is used for the oil based inks in typewriter ribbons. In a pinch, could one get away with a small application of light mineral oil? I sure wouldn't want to use WD-40, due to some of the additives, butI have to admit it did work well, didn't dry out quickly on the ribbon, but dried decently on the paper. Not far off from this wet fresh ribbon.
Off to clean type heads.