The Best file that i've run across is the "FSKS Tungsten Carbide file". It is either 2 or 4 file "inserts" glued to a plastic plate that is either 70mm or 100mm, depending on the model. Evidently the 70mm fit in many tuning tools such as the FK Multi-tuner. This "file" cuts clean and thoroughly. I suspect that it could cut through rock dings, but I would still prep dings with stones, since this series of files ain't cheap. The 2 insert models go for $30, the 4 insert for $50. The way they are configured, one couldn't use them with the SVST or Beast base bevel guides, only with Side bevel guides. With Winning Edge, SVST or any other side angle guides you might have to reverse the tool and use the solid side under the file, because the file might not span the waste "cutout". Since they are costly, don't ever space out and drag them backwards along the work. If you have that bad habit and don't realize that you dull files and edge by dragging, get rid of the habit! Looking at the edges after using this file ( with my home model electron microscope) the edge is smoother than any other file i've seen. For eastern ice, a light stoning for burroisty? might be all that is necessary for finish edge. Artech is the only catalog i've seen them listed, they are items 304-307. You rep types could probably figure out the distributor in a state WI. For an idea of what they look like try looking at Reliable Racing's picture of FK Swing cut combi w/Tungsten file pg. 74 (on paper(.