Dave, unless your car has been chemically dipped I am willing to bet you have some original paint.
Regardless, the paint companies should be able to convert the old codes to the newer formulas.
The codes for medium lime poly aka medium Avacado are easy to find
The old Dupont code is 5176
You will probably want to see what brands your painter is willing to spray. Companies like Dupont/PPG are still around in some form