Knife sheath

I bought a kitchen knife from DAISO, but it doesn't go with sheath. To make it safer at storage, I decided to print a sheath for it. After searching Thingiverse, I cannot found any model fitting this knife, so I use Fusion 360 to design one.

I first took a picture of this knife and set it to the canvas layer in Fusion 360. I sketched its blade with special curvature. However, my first work cannot fit the knife well because of the spherical aberration.

The uploaded file is the 2nd version o