The standing joke back in those days was each and every new Boeing airliner was a prototype!
Spooky 2,
Ain't that the truth.
Just about everything could be customer option.
Not any longer, the certification costs alone dictate a very standard aeroplane.
At one stage, I worked for a crowd who had about 10 or so 707 of various origins.
The only two that were common were to ex-Pan Am 707-321, with JT-4, two of the first ten delivered to Pan Am.
We also had the very last 707 delivered to Pan Am, a -321C, the contrast was very obvious in the cockpit. This -321C was a dedicated freighter, had never been a passenger aircraft, I never envisaged that a -320 could have such a low empty weight.
Even the two ex-Qantas aircraft they had were different series 707-338C.
You became very adaptable very fast.
The great thing about the 707 was they were so simple, of the flight controls, only the rudder and spoilers were hydraulic, they stood up to even the crudest conditions very well.