Yep, an exacto small diameter blade holder works great if you add a little padding to it. I like the blades with the curved hook bill on them, similar to the shape of the tool you built. Fine cross hatching can be used to create different degrees of shading depending on how close together the lines are. The cross hatching will take your work to a whole new level. India ink works fine for filling the cuts. But if you didn’t polish out the scratches it’ll accent those also.
Hungry Horse