I'm having rouble setting up my 60 1/2 and 9 1/2 planes.im using the versions with the ribbed iron bottoms. Basically, I can't get the blade angle high enough to get the bevel through the mouth. Or, one in a while when I do, the blade protrudes fully through the mouth asking the plane useless. These are "new" used planes for me, my old one didn't have this problem, so might it be the blades? Everything else seems to be in order. Very frustrating as I've got four of these to restore and can't get them to work becsude the angle is too darn lw.