repairing amplifier speaker terminals?

I have an older Rockford Fosgate P-450.4 that got some moisture on two of the screws that secure the speaker wire to the amp. The screws rusted and when I went to remove the wire broke the clamping mechanism that holds the wire. The amp still works fine but I cant seem to find a way to fix these two terminals so they will hold the speaker wire anymore. I pulled the amp and replaced it with a Kicker amp because they use set screws instead of the stupid plastic block and clamping mechanism that Fosgate uses.

I hate to throw away the amp and was wondering if anyone knew of a way to repair the terminal. If it's toast I'll just write it off, otherwise I can still use it in my other vehicle.

I read the "How to choose an Amp" sticky and terminal posts were mentioned and the style that Rockford Fosgate uses were frowned upon. I see why now!