Free: Contests & Raffles.
Uh, how bout those cables? I'd bet a case of cheerleader beer, that's the issue.
I would start by going after it with a wire wheel in the drill. You might luck out and not have a problem with the terminal to conductor, only the terminal and battery post. It's often worse there because you have a connection between dissimilar metals (copper, lead and whatever the bolts are made out of). The copper to copper connection of the terminal to conductor tends to be less problematic.You could also make your own new one, the tools and parts are widely available and relatively inexpensive compared with factory cables sometimes.