Carbide Tipped Straightening Hammer
These hammers are made by Knife Edge Works in Kentucky. They have a carbide insert in the tip for fixing warps in hardened blades.
To use it lay the warped on a flat surface with the knife laying like bowl so the ends are lifted up and the center is touching the surface. Lightly tap the blade in the middle of the warp making slight dents to push material around and it will gradually straighten out the warp. After grinding out the dents the blade should stay straight.