I too prefer natural materials. Since it is a 'using' or 'working' knife, and already showing some wear, I would look for functionality and aesthetics but not go too far with embellishment or the use of exotic materials at this point.
Cocobolo, Ironwood, East Indian or Honduran Rosewood all polish very nicely due to natural oils in the wood. I have worked with all the materials with files and sand paper only, no machine buffer or sander, and all come out very nicely. You can also use many stabilized woods like pecan and maple which handle aging and the elements quite well and give a warmer 'feel' than metals and some synthetics.
You could improve the look easily with fancy pins (using satinless steel and brass rods inserted inside a stainless or brass tube and filled with a polymer resin).
I have a Schrade LB7 Bear Paw I carry about to construction sites, so it got pretty beat up. About 10 years ago I dropped it, broke the very tip of the blade and cracked the handle. I took it home and stripped it down. I put on rose pakka wood scales and new threaded brass pins because I destroyed the originals removing the original scales. I added vulcanized paper spacers between the brass guards and handle wood. It still looks a bit beat up but otherwise fine. All the material was cut and shaped with a jewelers saw, files and sandpaper, and hand finished with 1600wt carbide paper, and I used mini taps and dies to thread the liners and pins.
