Hi, i found the Galvaknuckles hidden in Nuketown. It's quite easy to get a hold of, all you have to do is;
- Go to the truck in the center of the map (the one with the 3000 pay debris).
- Open it up, in the far front of the back-part you just opened there should be a pile of boxes.
- Throw a grenade over the boxes to the far front, and then one of the boxes should pop out.
- Behind the box that popped out you can now buy the Galvaknuckles for 6000!


Hope this was understandable, if you don't understand it, then i'll post a vid of it also