See if you can draw it to scale satisfactorily - if you can't draw it it is not likely you can engrave it. Get yourself a small triangular file (saw sharpening suppliers have a range of sizes) that will cut on the edges. You will need light, magnification, and a solid "vise" (anything that holds the screw solidly - creativity allowed). Determine if the lines are uniform width/depth or tapered width/depth. Practice on a "slave" screw(s) until you are satisfied with your work. Polish the screw head to very bright. File in the lines. Install. Smile.
DDA
