Ehhhhh I was all ready to echo to above and say shoot it, but in addition to trying to steel wool off the big spots I'd pull one of the bullets, dump the powder, burn it, and pop the primer. Just to make sure it all goes correctly. Maybe the one two up from the bottom, that looks like the worst and largest corrosion spot visible.
If you do that - at the end of the day you have a reloadable case if it all works fine. Worst (or best case, depending on your point of view) you find green powder and avoid an exposive round of plastic surgury.