Been a lot of years since I made up a knife, but I found a box of blades when i remodeled my shops, and i've been thinking on it. I guess I'll take a swing at this. Here's two I dug out this morning. I made these way back when I was muzzle loading. For me, that started out in Southern Ohio, and we weren't "traditional"... we were those crazy guys who still used those funny guns. Weren't any production guns or anything like that... we just had old family guns and wouldn't stop using them till they wore out... which they never did.
Anyway, if you look real close on the first one below, you'll see a little tit on the bottom of the guard. That was for seating a bullet in the barrel before you cut off the patch. I'd like to say the blade was mottled because it's damascus, but that's just 40 years of blackpowder specs and living in a sheath on the strap of a pouch.