Rear wheel cylinder blew out on the way to work today

Along with the brake shoes, wheel cylinder, and drum, there is additional hardware making up the drum assembly: return springs that draw the shoes back to a retracted position (good the replace these, as heat and age weaken them); adjuster hardware that help keep the shoe lining close to, but not binding against the drum; little springs + washers to hold the shoes snug to the backing plate; etc.
The factory service manual is excellent; try to secure a copy for reference.