Hello,

I use a triangle shaped needle file to reestablish/sharpen worn lead screws. No specialized tool, these come in a large variety of shapes and must be readily available.
An effective arch, if any, on the slick's edge would just show light at the edges if you were to hold a straight edge to it, or you might say something like 1/64 inch clearance there at the corners.

Greetings,

Don Wagstaff