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Hi OldOgre (and others). The big question is if any finish continues to exist in the damaged area or does the damage extend into the raw wood. You would have to apply a dye or stain to blend with existing before applying finish if the damage goes down to raw wood (like the marks left from fine tuners under a tail piece). I would tend to use boiled linseed oil over tung oil, but steveduf is the expert on these matters on the forum and I would defer to him.
I want to try Tru Oil (a boiled linseed oil based gun stock finish) but I have not found a good donor violin to try it on (I keep buying damaged violins on eBay for the project but find that their finish is too good to attempt to sand blast (with baking soda) to white.
Success is the progressive realisation of a worthy ideal. —Earl Nightingale.