I have been wanting one of these for about three years. I finally made one!
This was made from one of the cutters in an old broken pencil sharpener. It was a bit dull so I sharpened the cutter using the ancient method of soaking it in vinegar. Now it is nice and sharp. A bit of all-thread, between the knobs, holds it all together. Great little tool, Kind of a cross between a float, file and a spoke shave.