without having it in my hand, i'd say whoever used it before you altered the edge profile, either on purpose or by poor sharpening techniques. i own a sharpmaker. it's two angle set ups are what, 30 & 40 degrees? if that's been reprofiled, you'll have to remove a bunch of metal and it may take a while. it looks like it seen some use in its time, maybe it wasn't maintained at all. if you're not up to golddiggie's belt sander suggestion (i know i'm not good at it) find a little shop and have it professionally done. shouldn't be much over 10 bucks. then you just need to touch up from time to time.