I was sweating over this with my S/A 8-speed hub with drum brake, and it turns out that you can just rotate the drum brake arm so that it's in the right orientation- all of the torque is against the arm when braking, not against the axle flat- the outer brake plate was just held with a nut, and it would twist easily. I bet yours is the same- there's no reason under the sun why one rotational orientation is better than another when it comes to drum brake plates.