I can recall flying in one of the DC9-10's from LHR to MME in summer 1990, so they were still around at that late date. I was amazed to be served a full 3-course dinner with nice wine. The hostie must have been busy on that run. The food was far better than anything I have ever experienced in BA economy class.
My last ever flight on a short body DC9 was in 1999 in Mexico, jump-seating on an AeroCaribe flight into Mexico City at night with no other pax on board. Autopilots were u/s and the Capt. hand flew the entire flight in VMC with the help of a portable GPS! The panel was vintage Douglas circa 1965.