stumped by our woodwork
So many old houses have layers upon layers of paint on the woodwork that need to be stripped. We have the opposite problem. I think our woodwork is all chestnut, and it's never been painted...it doesn't seem to have any kind of finish remaining on it that we can see. It has taken a real hit over the years, with scratches and sun damage particularly on windows and sills (check out the corners of the window sashes in the first picture).
We're not really sure how to repair it or bring it back. We don't want to sand it heavily as that will dramatically change the appearance. It is pretty dark, but I'm not sure if that is the wood color or if it's been stained at some point, or if it's just got 104 years of dirt build-up. We definitely don't want to paint it. Is there a way to "feed" the old wood and then seal it? What would tung oil do? I've heard of Restore-a-finish...what would that do? I'd appreciate any advice I can get. So far all I've done is give it a light cleaning with warm soapy water.