Was any serious consideration ever given to extending Essendon instead of building Tullamarine?
.. where did you forsee any opportunity to extend any of the runways without disproportionate penalty expense ?
Who had the last flight out of Essendon, TAA or Ansett?
Probably need to qualify the question. I don't recall which tail was last out during the transfer to Melbourne but you need to account for the periodic diversions into Essendon (usually due fog). No idea if this still occurs.