Schwinn changed hands in about 2000. I bought a new Schwinn road bike in 1999 and with updates it is still going fine. It is a quality bike. Then the company was mismanaged in about 2000, someone bought them out and "they" whomever that is, have made junk ever since. They are all about milking the Schwinn name for all its worth. That happens with a lot of good companies- they build up a legend then hit a rough spot and it turns into a low quality sellout. It is a standard technique for making money in manufacturing, and it is not considered unethical.
My parents had some friends with one of these Mercurys. They had a 1975 Colony Park and it really was a nice car- very powerful, quiet, and smooth. Ford was good at making large cars at the time and they really were nice. Good as a new Rolls no, unless you think vinyl seats and cheap fittings are good. But for $5k you could ride pretty well in those days.