The Zephyr was sold as a 2 door coupe, a 4 door sedan, and a 4 door station wagon. It was a rear wheel drive car powered by a wide variety of engines. For most years, the base engine was the OHC I4, but they were also sold with a Thriftmaster Six I6 and a Windsor V8 - all the way up to a 302. The transmissions sold with this car were the C3 and C4 3 speed automatics and a 4 speed manual.
One limited edition version of this car was the Z-7. The Z-7 was a two door coupe with an I6 or V8 engine, along with several design elements like wraparound taillights that were not offered on the standard Zephyr. These models usually had two-tone paint, and are considered more desirable by collectors today.
These cars replaced the Comet in Mercury's lineup, and were replaced by the Topaz after being discontinued. During the mid-1980's the Zephyr was reskinned and sold as a Marquis. These cars also got an engine replacement, with the I6 out and the more powerful Essex V6 in.
These cars are becoming less common. If you need parts to fix one up, I suggest looking on eBay before paying outrageous prices at the auto parts store for parts that might not even fit very well. On eBay you can find lots of original parts, along with parts cars. It's also a great place to sell one instead of getting ripped off by a used car dealer.