If the bore is yucky, try putting a bronze brush on your cleaning rod and spinning it up and down the bore with a drill motor, well lubed with a bore solvent of your choice. Wipe clean. It might surprise you how it turns out.
For shot wads I would begin, and end, my search with Circle Fly. They have every size imaginable in nitro card, fibre, and over shot wads. Such is the selection and cheap pricing that I don't even think about punching my own any more out of found materials, and I'm a die-hard do-it-yourselfer. I've tried wasp nest, leaves, etc. and gave it up when I got blown patterns when I finally got around to shooting at a pattern board. I suspect it just doesn't have enough integrity to withstand the explosive effect of black powder to prevent gas blow-by up through the shot column. That stuff will do in a pinch if there's nothing else available. I can't help but think that the ancients who used it in the backwoods would have gladly given it up if they had access to proper wads. A buckskinner who is dedicated to "living the life" will argue about that, but it's a fact.
As for round balls, once you have the bore squeaky clean, determine bore diameter and use a ball .010" undersize with a .015 pillow ticking patch loaded as if it were a rifle. Accuracy out to about 50 yds. or so will surprise you.
