The OP recording is part of a fuller compilation of recordings to be found here:-
https://www.youtube.com/watch?v=MF5_hvE4WEA
To me they sound genuine rather than scripted drama recreated in a studio. The i/c discipline leaves something to be desired, the clarity of the recordings surprisingly good, and the accents varied and symbolic of the different backgrounds of these men. No doubt there was a certain amount of playing to the mike, knowing they were being recorded, but if I had to take a punt on it I'd say these recordings are from the over the Third Reich rather than from inside a BBC studio.