Notice the upper spring rides across the star wheel. On 60's Chrysler products, there was along with that spring a tab that when in a reverse direction of the drum, (brakes applied)the shoes movement in that direction raised the tab upward and when the brakes were applied again going forward, the tab would come down inserted into one of the points in the star forcing the star to advance one spoke of the star. The opposite side of the car star threads if I remember had left hand thread.