Moreover, the Design Authority for the RAF TriStar rests with Marshall of Cambridge and not with Lockheed.
Marshall does not have design authority for the RAF and any L-1011 Tristar, that is still held by Lockheed Martin.
From the Marshall web site: Marshall has full technical support and Conversion Design Authority for the Royal Air Force’s L-1011 Tristar Tanker....
So Marshall only has design authority over those portions of the TriStar modified my them. The won (under bid) Lockheed Martin for the technical support contract in 2005.