Here is my $0.02
Wheel weight lead is generally 8-12 BHN (hardness scale) You can increase the hardness by water cooling the lead to 20-24BHN. The box of round balls (Hornady) I bought from Cabelas is an 8 BHN, What does this mean? I dunno, they are just numbers.
I guess it all depends on what your trying to do. If you are to be historically accurare, you should use what was available in the area, and time you are "living". If your hunting or match shooting, you probably should have the best lead available, because at that point the target needs to be hit in the dot, and the deer needs to be hit and dropped asap.
Living in Vt I've read stories of turkey hunters, using rocks, small nails, broken up shells, glass and hard ground up, broken up scraps of whatever they could find, to load up and fire at those birds. Any they did. They actually did such a good job back then, that they destroyed the turkey population. It took untill the late 1970's to get turkeys back to a level, where we could hunt them again.
Traditional for Vt is probably different from traditional in Va. I dont think there is a perfect lead, or method for round balls. But its fun trying to get there.