1984 was a booming year for the gray market, and quite a few AMG modified SECs from that year made it into the USA.
AMG was an aftermarket tuner, so its name would NEVER show up on the US title from any state.
If it was modified at the German AMG factory in Affalterbach, a good sign it was an AMG car would be the factory metal AMG build plate you might find on the driver door jamb or on the front radiator support. Though not EVERY one had them.
Many were modified by authorized American AMG tuning shops AFTER they got here from Germany. AMG West in Richmond Calif. Richmond Mercedes
is the last one standing, but at one time there were many, AMG of Missouri, Beverly Hills Motoring Accessories, AMG in Westmont Illinois, and others.
Each AMG car was modified "a la carte" either engine, suspension, transmission, interior, wheel, ground effects, or other accessories, as the customer ordered, so few were ever alike.
The basic rule was that any three modifications entitled you to the AMG trunk script, butit was not strictly followed. If what you say your car had on it was really AMG original mods, it sounds like it qualifies as an AMG car.
Undeniable AMG providence is supplied by the actual paperwork from the AMG factory or the Us tuning shop, but since the latter from 1984, all but one are gone, and the AMG factory has not kept records from those years, the chances of tracing an AMG pedigree on cars that old is slim to none, at this point.
You can call your car an AMG. Go ahead and buy an AMG trunk script, but get the period correct one, that looks like AMG
and not the new ones, that look like ///AMG. They are on ebay, and some are Asian knockoffs, but the real ones would be in a shrink wrapped package from the German factory with the Affalterbach name and address on the back of the cardboard package they are in. They typically go from $130- $150.