Re: German scientists, Black Knights and the birthplace of British rocketry
Seconded. It's been a long time since Channel 4 made their 'Britain's Cold War Super Weapons' series and I don't think it is (legally) available.
BTW. If you haven't read it; 'Vertical Empire' by C.N. Hill is a good look at the Blue Streak, Black Knight, Black Arrow and ELDO programmes.