Ray, I've reviewed this a second time - which included a study of what has been sent by other members.
1. You do not need UV protection indoors unless someone will be using UV bulbs (which is highly unlikely). I am certain Dan already knows this.
2. Thinking about what Jim (Marco is his dog's name) said, I now agree that the fading is a result of uplighting - review the photo and note how the partial ellipses are aligned with the coursing of the wood planking - that IS EXACTLY how the wood would fade in that scenario.
3. One might assume that uplighting (from a previous owner) would have left screw hole "scarring" on the walls, but this could be avoided with an adhesive mount.
4. My wife and I have been told "Aspen Siding" on numerous occasions when looking at mountain properties (such as chalets, cabins, etc.). It refers to something one might see commonly used in Aspen, Colorado.
5. I would bet that wood is Southern Yellow Pine, but my earlier recommendation of mineral spirits is NOT GOING TO HELP.
6. Unless you wish to refinish the entire wall, you will probably do best to hide those spots with some framed art. Good luck!
OPG3 Tweak everything!