Such a lovely, lovely room, the trim is wonderful; so well kept it looks brand new. Though I like the subtle texture, as others have suggested, I agree that a light wash would enhance the details of your wainscott. Don't know that I'd paint it copper or a similar metalic color, I think that in a room like that the wainscott was supposed to look like anaglypta paper, which was supposed to imitate fine plasterwork. In case anyone else is interested in a similar treatment for their walls, sheet metal wainscottis still being made by the F.W. Norman Corporation in Nevada, Missouri. They also produce ceiling panels, siding, roofing, cornices, moldings, and neat-o decorative ornaments in zinc and copper, all made right here in the U.S.A. (Disclaimer: I have no financial interest in them, other than the fact that I'd one day like to give them large amounts of *my* money - I have a substantial wish list complied from their catalogs - VBG) Here is a link that might be useful: W.F. Norman Corp

"Does chairrail and existing woodwork have to be removed first?" Absolutly not,,,,,,,,,,,,,,,if you cut every piece of wainscoat to precisly fit. I find it much faster removing existing chair rail and woodwork then install new chair rail with old floor trim when wainscoat was finished. If existing rail is recessed correct depth for wainscoat which is rare it can be reused.

Definitely get the shell done first--I agree with Anglophilia to remove the wallpaper and do it right. Here are some of my favorite dining rooms for inspiration: Country Swedish: American Colonial with nice contrast between formal dining table/chairs and country hutch: Country English (note the applied molding instead of a full wainscot): Formal 18th Century with stunning scenic wallpaper: Formal 18th Century with very highly paneled walls/neutral palette: 18th Century dark Queen Anne furniture with light and bright wallpaper, rug and curtains. Eclectic formal dining room with lots of color, pattern and metallic finish:

swiss coffee is a nice color, I had that on my only kitchen ( under Reno right now) is N facing too, I think I will go with the same color. This is what it looked like.