It is my understanding, if I'm wrong I'm sure someone will correct me, that you are correct in saying that a VC-10 style aircraft will not be designed to built again, is because of the four engines mounted on the tail. The FAA will not issue an airworthiness certificate to any aircraft with two engines mounted side by side due to fear of un-contained massive engine failure taking out two engines at the same time. Therefore, other than I think some Russian designed aircraft, the only aircraft with four engines tail mounted are the VC-10 and the Lockheed Jetstar. An aircraft designed like the Comet would have the same problem.
Military aircraft of course are exempt.