I may be wrong here, BUT I recall an old (departed) friend from the Essendon Airport Fire Service of the time, saying that they were training at Tulla and were on site there whilst some of LBJ's entourage of aircraft needed to go there for refueling? reloading and take-off? Or have I got the occasion wrong?
LBJ visited again for Harold Holt's funeral and his B707 landed at Tullamarine.Construction at Tullamarine was obviously still in progress.
I only discovered this when I stayed at the Mantra hotel at Tullamarine, where they have a series of old photos on the wall near the elevators.