There really only seems to be one void on the one corner.
as far as the wood wedge goes, usually those are made from some sort of builder grade softwood, like pine or Douglas fir, and neither of these sands really well, so it’s easy for the shim to look bad when sanded on the coarse type of belt Vaughan likely uses for that part of manufacture.
The only real way to tell if the hammer will be fine though(( and this is for hammers that look good too) is to whack it a dozen times against the glat on a tree stump and see if the head loosens up.