Can anyone shed any light on an old Buck Bros framing chisel I acquired recently. It is 17" long with the handle and has a 2" blade. Specifically I want to know if blade is supposed to be curved upward. The curve starts about halfway down the 8" blade, rising about 1/8" at the cutting edge, relative to the heel. I just want to know if I should worry about straightening it before I clean and sharpen it. Someone on another forum said something about some of these old framing chisels being curved for clearance, but I can't find anything else. Thanks.