I can't even tell how the armature would come off the crank unless it will just pull off. I thought there would be set screws somewhere. The way that bushing is worn on this one it is almost impossible to tell what is part of the bushing and what isn't.
No setscrews...just slides off...well, supposed to! All that holds everything in place is the bolt & washer in end of crank. Your bushing seized due to a bearing at one time locking up & heating/fusing the bushing to the crank.