...when you have as much free time as I do...
Before:
After:
Next steps are to clean a little more around the vertical grip, fill in the screw holes, and give it another coat of Krylon.
I used a pistol grip from a Kraken AK.
I started by dremelling a hole in the top part of the pump big enough to fit a screw and a screwdriver/drill. This hole is covered up by the barrel so there's not a gaping hole on on side of my pump. I then drilled two small holes in the bottom of the pump through the top. There is about a quarter inch of unused space in the bottom portion of the pump, so a screws can safely be used without interfering with the shell tube.
I shaved off the little nubs of the pistol grip that keep it in place and filled it full of fiberglass. I shaved some of the "ribs" off of the bottom of the pump handle to better fit the AK grip. I stuck the grip over the pre-drilled holes and taped in place, then let it sit for half an hour. I took the tape off and she was really stuck on there good. The fiberglass had hardened by this point so I took a screw and screwed it through the pump, directly into the fiberglass. I then dremelled a good chunk of the remaining fiberglass off and got lazy and left the rest.
I also decided the saw off the red tip instead of just paint it black.
I got bored, sue me.