Hard to see from one picture. But it looks quite convex behind the tang then a little concave or with a dip approaching the comb. You want smooth transitions and continuity of form. Also it must be perfectly rounded or egg shaped in the wrist, not oblong (not square with rounded corners). I have made a series of scrapers with semi-circles of different diameters cut into the edges and use those to find and fix flat spots wherever things should be round or elliptical.
