Sorry about the bout of exuberance.
I believe this has been something that's been scheduled for a while now. As I understand it, the lagging absorbs water and then holds it against the boiler causing rust. In the weeds, and in the shade of the cottonwoods, it doesn't get much of a chance to dry out. Moving it to a sunnier spot, or - even better - to the engine house will allow it to dry.
Don