Kleinmachnow, the home of boy spy Martin Rauch, is a real place.

One of the writers was a listening post person back in the '80s in West Germany and said he based the premise on things he saw and heard there.
He said they had a mole where he worked. Because the Soviets and others they were listening to used their personal names on the tapes, taunting them.
So they knew they had a mole on their side, because the enemy knew the names of the people who were listening to them.
So he seems to have a lot on which to base the series.

Fantastic, thank you!

It's all based on real events which took place during that time period - The maison de France bombing, the Abel Archer exercise, the demonstrations, etc.
The characters are fictional, although there is obviously references to/period footage of people who were around then and integral to the plot; Ronald Reagan, Carlos the Jackal, etc.