One of my jobs at the RTO in 1969 was to escort the bus trip with a German driver and a baggage truck out to Tegel for the Pan Am 707. Sometimes the flight was scheduled to land in a secondary UK market, like Manchester, and sometimes in a secondary German market like Dusseldorf.
The Pan Am agent was an old-timer, so when I wasn’t sure how to handle something I leaned on him for advice. As that was their only flight from Tegel, he must have had time for coffee. Air France also had one flight from Tegel to Paris with a Caravelle. There were a few charter flights and that was it.
-- rwr