Geo Jeff--I would tend to think your bus was the recipient of government spending gone amuck.
If a bus was past the age of replacement I wouldn't put another dime into it. If it flat out died dead for any reason I would have it towed back to the shop to be used for parts or trade in.
School districts can purchase used buses from other districts or from a dealer and put them into service as long as they meet the minimum spe'c's. To my way of thinking it would be better to purchase a $4,000.00 bus than to put $20K into a bus that is worth only $4,000.00 no matter how nice the bus might be.
Both of our church buses came out of the Toppenish SD. They keep their buses up and spend the $$$ to keep them nice. Even so, when we got our second bus from them I swear they went through the fleet and put six of the absolute worst tires on our bus. There wasn't one that wasn't legal but none had much usable tread left.
In regards to the school in question, you did see I mentioned Bethel SD didn't you?