Over the years of use my Model 100 keyboard has received a couple dings, most often from pens that have dropped on it, many of which leave white marks. A few of these have over time turned back to the color of the walnut finish, but one in particular has stayed white, and irks me when I look at it.
Does anyone have a trick to turn these back to the natural color of the finish, more quickly than waiting it out?
A few options. With a photo might be able to narrow it down but wear on wooden items is a feature, not a fault.
Try a clothes iron. Heat and steam will lift indentations in wood, the finish might inhibit this. Use a towel or some other cloth between the iron and the wood. Should be obvious but try to keep steam from the keys.
Gentle use of a hair dryer or very gently use a heat gun might also remove white in finish. If this still doesn’t work you’re getting into more advanced refinishing techniques.
Super glue is used by luthiers to maintain a high polish finish on guitars fixing minor dings and scratches. Fill, level with polishing sandpaper.
Other options could be applying a drying oil like boiled linseed oil or tung oil. Make sure you follow disposal instructions for oily rags.