If the pipe looked like the photo, I'd say don't stain it, the way other posts do. The Dunhill smokers are a discerning crew, so i assume you are restoring this for your own use, if it does not come out looking just like a Dunhill of that vintage "should." But the process should be educational. You'll learn a lot, and if you get it pretty well right, it could be a real treasure for you to smoke.