Erik:
If that the fixed blade aluminum trainer version of a "tactical folder" that I have, here are four ideas for fixing it up:
1. Drill a couple of holes in it and "Strider-Wrap" the handle with parachute cord. Instructions can be found here:
http://www.striderknives.com/html/handlewrapping.html2. Go to the hardwear store and get some of that "dunk-it" type insulating handle material. I don't know the exact name, but ask the salesman and any Lowes or Home Depot should have something like that. Then just dip as many coats as you want to get the thickness you want. To make the edge nice and crisp, take a metal ruler and a utility knife and cut the ends to make them "covered and alligned."
3. Go to the auto parts store and find some rubber hose material that will fit over the handle. Then using a hot flame (boiling water probably won't cut it), "heat shrink". It probably won't look great, but it ought to work.
4. Get some micarta, G-10, or some sort of high speed synthetic material like folks use for handles on real knives, cut to size, rivet in place, and then use a sander to blend the edges of the metal and the handle scale. If you get really carried away with this, you could even purchase a pocket clip (I know Emerson Knives sells extra clips, other manufacturers might as well), drill a couple of holes, and use a tap set to thread the holes for the pocket clip and the handle. Then you can clip the knife inside your pocket or waistband to help it stay put until you are ready to "quick-draw."
Dan