The pin norm is just the mark left behind by the locking collar grub screw.
I spent several days replacing the same type of bearings in a header last week. Because of the eccentric locking collar the bearing always has a gap between the shaft and inner race. water gets in there and they lock on. if all else fails the bearing itself is not terribly expensive, i have in the past either split the outer race or broken the ball cage inside the bearing to separate the bearing and then cut the inner off later
