Today's update:
The bike arrived via FedEx, and wasn't damaged in shipment: it couldn't be, the seller had wrapped every tube in cardboard and bubble wrap. It took me about 20 minutes to unwrap everything! Meanwhile, I had contacted the seller to see when the last time it was ridden, and when the last time it was serviced. He said he had bought it at an estate sale 5 years ago, and had never ridden or serviced it.
I gave it a good degreasing and washing. The crank and rear wheel seemed a bit stiff, and the front wheel hub had a lot of play in it. Since I didn't have the proper tools for this type of bottom bracket, I took the whole bike to my LBS. The owner there spotted the same stuff, plus a (slightly?) bent rear axle, which he said is fairly common with freewheel type wheels. He's going to give it a complete service and tune-up, and I'll have it back tomorrow afternoon to take for its first test ride. I'm also having him put new brake pads on as the ones on it are like stones. Thanks to those who advised servicing the bike before riding it!
I did a quick weight of the bike (including the aluminum rear rack which I removed shortly afterwards). Without pedals, it was about 25.8 pounds. BTW, someone asked about the wheels, and they are Araya 26x1-1/4 with Shimano hubs (didn't see anything about what "flavor" of Shimano, so maybe there was only one back then). They are heavy, but I didn't weigh them. The tires look quite good, barely used; didn't note brand and size though.
Thanks again for all the comments, suggestions, advice; keep them coming.
Regards, Dick