I will be the first to admit I know very little on the subject, but when I think of German traditional knives, I think of the folding hunter.
Black stag scales, spearpoint blade, lockback.
Hubertus has already been mentioned, and they make some nice autos, but also non auto lockbacks in the traditional style.
I expect there are a lot of other manufacturers that make less expensive versions, but the language barrier will make it tricky.
I wonder if there's a german member here who could help you out?
There is a gentleman who's name escapes me, who does some excellent youtube reviews and seems to be extremely knowledgeable.
Maybe he'll pardon my ignorance and chime in?
Incidentally, I had the opportunity to handle a Hubertus lever lock auto when visiting Amsterdam a few years ago.
It was absolutely stunning, and when you fired it, you could just feel the quality. It was so smooth, and the blade locked into place with a satisfying 'clunk'.
There'a just something about leaf springs that feels better than a coil spring.
I have dreamed of owning one ever since.
If the non-auto versions are of a similar standard, they are worth every penny.