drums rotate forward but not backwards

OK, 57 Series 1. I had trouble removing the front left drum, eventually got it off and thought nothing of it. I replaced the brake cylinder and had trouble fitting the drum back on. The rearward shoe had to be pushed in slightly to allow the drum to slide on. The wheel would then rotate forward, but would lock-up if spun backward. That was likely why I had trouble getting the drum off in the first place. It almost seems like one side of the wheel cylinder pushes out too far and forces the rearward shoe out just a little bit.

Any ideas? Thanks....