Brake Drum Issues!

Coming home from work I heard a slight ticking noise from the rear followed by the bus starting to hold back. I wasn't far from home so kept going hoping it wouldn't get worse. When I arrived I took a look at the rear wheels and noticed the drivers side rear had gone from a bright white to a nice yellow colour!

On closer inspection it's hard to work out exactly what's gone wrong but one retaining pin has gone, the other fell out, the springs were in the bottom of the drum! The whole thing must have got really hot as you can see by the colour of the wheel. The shoes had no material left and the cylinder looked pretty jammed up to.

Obviously I need to replace the lot, I need to have another look at the drum but think that's scored up beyond repair. Better check the flexi hoses to. Oh well just another job to do!!