While I never needed to smooth the edges of a file, I would think it could not hurt to try a grinding wheel or even another file. I would be sure to wear gloves and eye protection and clamp the work piece in a vise or with vise grips. Good luck with your project.
36. Gotta look in the table, it's down there
If it proves to be too coarse there are wheels with a finer surface to try.
It comes with a bunch of plastic spacers that dont take long to create a wobble.