The ones I’ve done I use paste wax on the barrel. I also found that real sinew, or thin rawhide wangs, shrink with the rawhide. This keeps them from gaping at the seam, like they tend to do with stuff that doesn’t shrink. The last one I did, I used a baseball stitch, instead of a whip stitch, which helped as well.
If you want to simulate that hundred plus years of grunge, get some Lincoln’s medium brown shoe dye ( not Fiebing’s). Get a dry rag, and a wet rag ( not damp ) and a bottle of Lincoln’s shoe dye. Put some dye ( less is more) on the dry rag, and rub it on the dry rawhide ( no need for perfection just get a little on most of it, then immediately rub it down with the wet rag. This will lighten the color, and give it the random colors you want. Although Lincoln shoe dye is a spirit based dye, just like Fiebings it can be blended, and lightened, with a wet cloth where Fiebings can’t.
Hungry Horse