I used a file on mine then emery paper then the 1000 grit, finished it off with a leather strop and autosol polish, works a treat. Glue a strip of leather smooth side down to a flat piece of wood for the strop...you'll have bevels you can see your nose hairs in! For the fiddly bits underneath I just perservered with the sandpaper. That's the worst part. I should have sent a strip of leather but wasn't thinking. Let me know if you need a piece...