Amusingly enough.. when I first saw the schematics for the Shiskebab, the first thing that came to mind was a spinning fanblade on a long handle, covered in flames.
To be honest, such inventiveness shouldn't be beyond the grasp of an intuitive person with the right kind of twisted imagination, lots of scrap and most likely the Blood Mess trait backing them up.
Just imagine.. a long, hard plastic pole with wires all up inside it, leading out into a large energy pack on your back, charging electricity into the jagged piece of scrap metal you've mounted onto the other end. ..Or maybe you just mounted a slightly dismantled power drill onto the end instead.
Imagination is the mother of creation.
Aside from putting together your own weapons, I don't see why someone wouldn't just use something like a jackhammer, or more accurately, the kind that you can carry and hold upright - they sometimes use those for walls and such, as I recall. I find it hard to believe that all manners of guns survived nuclear hell, along with cars and various other machinery, but nobody's ever thought to use a jackhammer to tear into people.