The Signature Series was a step up from the base Mark VI, but not quite as snazzy as the Designer Series cars (which featured styling by Emilio Pucci or Bill Blass).
The Mark VI was built on Ford's Panther Platform, the same one used all the way through the final generation of Ford Crown Victorias and Mercury Grand Marquis and into our current decade. It was a good 500 pounds lighter than the Mark V, but quite a bit less opulent as well (in spite of the opera lights, porthole windows, and padded roof).
This one has the then-very-futuristic digital instrument cluster and trip computer.
Electronic fuel injection and four-speed automatic overdrive transmissions were still worthy of bragging rights in 1983, and so this car has badges for both features.
Power came from this 302-cubic-inch V8, which was rated at 130 horsepower for 1983. That's about 31 pounds per horsepower; compare that to the 24 pounds per horsepower you get in the least powerful version of the 2017 Ford Focus.
The MSRP on this car was $23,340. That's just over $58,000 in inflation-adjusted 2017 dollars.
As well-designed as a phonograph turntable or a 16mm film camera, the most desired possessions of the era.
An electronic brain that manages five separate engine functions!