I never sharpen the sections.
I replace the bad ones rather than sharpen.
I also bought a whole new sickle about every 600 acres or so.It might be good for you to start with a sickle with bolt on sections.
Bolt on sections can be replaced while the sickle is still on the mower without to much trouble. I also replaced the rivoted sections while on the mower with a rivoting tool.Sometimes it involed removing a guard to do so.