It took me and my son about two hours at my dad's farm with shovels and rakes and implements of destruction to push all that dirt into a gully (there was already a pile of garbage at the bottom of it, and rather than bring that pile up, we figured we'd just put our pile with it).
Anyway, for the first time since we bought it, the air in the big house actually smells pretty good now. That rotten stucco had a lot of earthy mold smell to it, and I had hoped it would make a difference to remove it, but essentially it seems to have entirely eliminated the smell, which I hadn't really dared hope for.
So what's stucco, you ask? Turns out that stucco and plaster and mortar are all pretty much the same thing, which surprised me. Anyway, the basement walls are stacked limestone that had had stucco on it, but the utter lack of drainage for so many years put most of it on the floor. Now that it's gone, I'd really rather put some back; that's the point of having the gutters, after all.