So i finished slotting it the other night using my cheap radioshack clearance priced needle files and some 600 grit sand paper. Using the carbon nut actually worked well, given a lot of time and care to make the new slots accurately line up. I simply took a mechanical pencil, lined up first the front of the now shaped bone blank, made very small marks, then turned it around and marked the back. This was necessary because the headstock is a 3 and 3, so the slots are all slightly angled. Next I made a line indicating the slot using an exacto, and then my trusty butterfly knife, since it has a wide, thick blade which made a deeper score. this helped quite a bit. I was then able to seat the edge of a file into the fine groove left by the blades, and then gently begin deepening the channel. Once I had a nice thin groove for the round file, I finished the slots with the round tapered needle file. One thing to be careful of is the front edge of the nut (closest to the bridge). A slight slip of the hand, and you can ruin the front edge of the slot, causing the string to pivot inside the nut channel when under shear (bending of the string). This happened a few times, and I had to file the top down and rework the slot. I almost ended up with it being too low again. Once the slots look good, I take a dial caliper, and measure the slot width to make sure it is appropriate for the intended string gauge.

The process was time consuming, and I'm sure it can be done faster with the right tools, but I am very pleased with the result. It sounds and feels great, and the strings move better that ever when tuning with no binding or pinging. I will take some pics and post them today, after I have played it a little more.