Just an update in case anyone is curious: I had my car towed to Liberty Auto on N. Henry Street in Old Town, where David Rockwell told me that both the water pump and thermostat were shot. He replaced both, as well as the serpentine belt, which was apparently somewhat cracked and needed to be removed anyway (I think). He also pointed out that I should have my valve cover replaced soon and that my car will require brake work in the not too distant future (and that it's due for new spark plugs), but I opted to defer those items for the moment, as even with the shop's generous DCMM discount, the total for all of that is quite daunting.
I picked up Emma (the MCS) yesterday and drove her home with no problems, but I admit I'm pretty nervous about the future; that she's awfully fragile and terribly expensive. Are there any reasons that (a) I should be nervous now, about the valve cover or any internal damage to the engine from the overheating incident (I should note that David said that the oil didn't seem to have any coolant contamination, which was a relief), or (b) I should start thinking about other major potential problems down the road, and/or begin to think about replacing the car?
Thanks again for all the help and support.