It features Herr Inspector Loman, who was also in M as the cop trying to catch Lorre before the underworld did.

Oh, neat. I didn't realize he was a recurring character.

though I suspect that such a series, if historically realistic, would have to have ended with him being fired and possibly arrested once his quiet stubbornness and honesty butted up against politics.

That makes me think of The Grand Budapest Hotel. I did not expect that particular fantasia to run up against real history as hard and as truthfully as it did (and it was a better film for it).