Roughcut Gear Replacements

Hey guys and gals, I recently bought a broken roughcut from goodwill in hopes that I could fix it. After opening it up, I realized that the gears were stripped. Notice how I said "Gears"? Well instead of it being that tiny gear that people always manage to strip, it is that; and the gear that is underneath the largest gear in the blaster.

I was hoping if anyone could point me in the right direction as to where I could find a FULL gear replacement.

Thanks for the help,
-Slingeh