Thank you all for your interest! Ok, I'll try to answer you all at once.
First, I did call the previous owner and told him that I had to have it towed halfway home, and he was more surprised than I, as it had served him well with no hint of engine trouble since he bought it new. He hadn't put many miles on it in the last couple of months or so, but did drive it about once a week to make sure everything still worked.
I believe he will be receptive to work out some sort of settlement, but I'm leaning toward making it a project.
Now, the symptoms. On the way home, I first noticed a lack of power when I tried to kick it into passing gear starting at about 60. It didn't 'launch' the way I expected, but felt more like it had a clogged catalytic. It drove fine a week ago, and had lots of pep, but not going from 60 to ?. From there, the performance slowly degraded over the next several miles, until I pulled off the freeway to go to a barbecue. The engine stalled at the stop. My wife, in the chase car, went for gas because I was driving near empty and thought that I just ran it dry. A single gallon seemed to revive it, but it was still stalling at every stop on the way to the gas station just two blocks away. By now, I was noticing that the oil pressure was borderline, too. Incidentally, while waiting for my wife to bring gas, I called AAA and found out they won't provide road service to a car that isn't currently registered! I was madder at them than I care to describe.
So, we limped to our barbecue, then headed for home, still over 20 miles away. (Total trip distance was 44 miles). The car made it about 5-6 miles before it started to really drop in power, and now it was overheating, too! Keep in mind that the engine was getting noisy, no doubt due in part to oil starvation. I did check the oil level at the gas station, and added a quart just to be sure, but it didn't help.
My mechanic says its noisy in the bottom end, so I need another engine. Do you all think that the oil starvation may have killed a bearing, or is the low oil pressure is causing the noise... I hope? What is the likelihood that the first cause is a blown head gasket? That would explain the overheating, but you might know if the loss in oil pressure is also a possible effect. When I checked the oil, first at the gas station, then again when it finally breathed its last, the dipstick came out looking like it was "smoking", not really smoke, but vapors coming off like there was excessive blow-by.
I did finally get AAA to come tow the car to the mechanic by having my wife make the call, and not tell them what I had told them before. She was told by the AAA person that the driver would ask to see the license and registration, but they never have, and fortunately did not this time.
The most amazing part of this whole story is my wife never rode in the car, but still likes it better than my Volvo, and thought I should make a project out of it even before the Volvo suffered a major failure TODAY ON THE WAY HOME FROM WORK! I think I need a vacation! Incidentally, my wife drives a 1994 Chrysler Town & Country with over 225,000 miles. The Volvo had over 250,000 miles, so it'* due, I guess.
Thanks for your help!