First thing I thought I would try out of my plastic parts was the belt splitting jig. I managed to drill the holes ok. The slot was a little trickier, I used my dremmel clone to do this. A tip I have found for drilling the holes in the plastic if you are concerned about it "biting" into the plastic and cracking it is to run the drill in reverse and it tends not to grab at the plastic, but takes longer to drill the hole. Below you can see the finished jig. It worked perfectly and I now have the belts split successfully.