I am in need of checkering a bolt release on a Mauser what would be the correct, or best lines per inch for something that small

I prefer fairly fine checkering. Something in the area of 50 lpi.

I prefer a #1 (40lines). To me a #2 (50lines) looks best but doesn't FEEL as good. Also depends on whether it's angled,rounded,or flat. If it's rounded I use 50 lines.

Who could I send this bolt release to for checkering. I don't have the need to purchase a file for just this job. You can PM if you wish. or email at greenrivergw@msn.com