Jeff is right about how the surface is finished and so is Bob on the brew. I haven't done it exactly like Scott's directions but have used an oil leather dye then mixed dry Black tempera paint with Danish or Tung oil, painted it on, let it dry good and then rub it back with 0000 steelwool. It leaves a a nice patina. I painted the butt with it too but it takes a little more work to get the wood cleaned up. Linseed oil, Walnut stain and the Black paint also works. For both start with the powdered paint and ad the liquid until you get a thin pain, you'll have to experiment with it I work by eye and don't measure things.
Another option: the bottom one here was painted with flat Black, sanded back, stained with Brown leather dye and coated with Brown shoe polish and buffed. You can adjust the color as needed even add more as long as you don't put wax on it. Although that, the wax may add a more used look since some of the mixture is not going to stick well to it.
I will be interesting to see what you come up with.
Tim
It brings out the scraping marks:
