What I might suggest is that you smooth the edges of the piece you are working on before running the groove line round as I can see a lot of bumps that has caused an uneven groove line. It also look as if your groover has clogged at one point as the bottom of the groove is showing a number of stutters.
I have mentioned that I will be attempting a bit of weaving on the front side of the sheath. Here is a youtube video that gave me the idea. Just start watching at about 2 minutes and end about 7 minutes. I do not intend to use any horse hair. I am going to use a blue suede to incorporate that color with the knife and some copper beads. Hopefully. I have never tried this before and I am a bit leery it will turn out. My fingers are crossed.
The sheath will get two-toned. Dark brown edges and tan centers. I cheat when it comes to coloring. These are my best friend. I use a sharpie to color the groove line.