What she didn't know was that the day before, I'd run the engine just to keep things charged and lubricated and whatnot, and steam had issued forth. As near as I can tell, the water pump shaft seal let go and coolant is coming out of the weep hole (I can't wait to see what the Google searches look like for the next week now that I have "weep hole" typed here. Twice.) My Bride is picking up a water pump in Springfield today and then we'll see.
I HOPE it's the water pump, because that actually seems pretty straightforward on this model. Last time I was losing coolant, it was a freeze plug, and that one cost me some bucks at a Chevy dealership. If this is the water pump, it's a shade-tree solution.