I recently liberated an 8 inch Ontario blade and it has a curious grind. It's the birds head handle not the hickory one. One side has almost a gradual taper to the edge I say almost cause there is a second bevel but the other side has a distinctive second bevel at a harder angle. Is this normal for them? Or is this just an off blade? I don't see any signs of reworking unless it was done many many years ago.