Must have had some serious heat on those drums to make them crack. I would make a call to Kaiser Brake in Eugene or take a drum to a heavy duty truck parts house and see what they come up with.
Also have the truck shop take a look at the drum and get their opinion about getting it turned
I don't remember which front end we have (Neway I think), and you should have a parts breakdown in your documentation. Give them a call for parts.
2002 Country Coach Intrigue