Let me add that hand checkering is a difficult trade, mastered by relatively few workers. Moreover, there are several types of tools, with different "pitch" (distance between 2 adjacent grooves), and that for the outside groove you need a special tool.While I have high respect for your skill in using files, chisels a.s.o. please allow me to doubt about the chances of obtaining a decent result.
During a short course of "home gunsmithing" near Brescia (area where most of Italian gunmakers are based) an instructor showed us that he could cut 3-4 lines before spoiling the job with a wrong stroke and concluded that hand checkering should be left to skilled workers, almost exclusively female.
Presently, most of industrial checkering is machined by laser with multiple spindles (more than 2 if memory helps) while high grade stocks only are hand checkered by the a.m. ladies.