Jeff, since you are refinishing the drum, I would go back with Aluminum washers all around, Stainless for six or more ply. If you do original steel, you saw what you cleaned off and it takes the route of the grain too., if you use Copper or Brass it will green up on it, but, it you use polished Aluminum washers, it will take the shape of the shell and none of the other sh*t will happen. Put originals in a sandwich bag and they go with it.
A buyer will look at superior woodwork and those ugly fasteners, but new washers blind out the screw.