If you want to produce a valid argument against this stupid 20 or 15 years old aircraftt ban , just use the ICAO statistics: today the region with the oldest fleet in the world is North America, and the region with the youngest fleet is South America, compare the incdents and accidents rates of the both regions.
Also if you take hull losses per million departures, The Russian the good old Tu154 had a much better ratio than the Boeing 737, not to mention MD11s or FK28s. Safety is a bit more complicated than the age of the aircraft.