I am fairly new to Pprune and to this thread, which I have speed-read to catch up!
My father worked for the government and was posted to USA in 1964 when I was 8 and my brother was 10, we were at boarding school in UK and flew out to USA for holidays.
We had flown on several 707s and DC8s then had our first flight in a Super VC 10. Even at that tender age we sensed that it was the greatest and were thrilled by the 10, and the impression and love we both have for this plane is indelibly etched in our memories.
On our first flight we sat in the rear most seats and I had the aisle seat, I recall looking up the aisle to the flight deck curtains and to me it seemed like we were almost vertical and going up like a rocket. Certainly, as others have said, there was something "Thunderbirds" about the VC 100. Going up and down the stairs just in front of the Conways and peering into them was part of the fun.
As for the history of the rear engine/T tail design I have a relative who worked in the British aviation industry at the time, and a US friend who worked in aviation over there. Both have told me that part of the deal for US help in both World Wars was a Technology Sharing agreement, but often this was "influenced" by powerful US interests!
Both these people have told me that Boeing needed more information about the behaviour and performance of rear engines and T tails and knew that UK was ahead. Plans were drawn up under the Agreement for Boeing staff to visit HS for 3 months to learn from them, then later HS were to visit Boeing for 3 months to see what they knew. A while after Boeing's visit HS asked when they would get their reciprocal visit to Boeing. Boeing had learned all it needed to known and replied with words to the effect of "You don't!"
British history tends to politely "overlook" matters like this, and many projects such as the Miles M 52, the UK rocketry programme, TSR2, and our nuclear weapons programme were given various public reasons for cancellation, but it seems that many were actually cancelled due to US interests. It is widely known that Canada cancelled its Avro Arrow due to US pressure, but when UK projects were cancelled in similar circumstances different reasons were given to avoid damaging our Special Relationship.
This is what I have been told by people on both sides, and it does sound plausible to me, but happy to be corrected!