Nice fix, Mill.
I can't tell you much about your knife, but I included a picture of my "Slim" with Rosewood covers for comparison.
It does seem unlikely to me that Hubertus would use faux stag and not the real-deal, but who knows.
My understanding is that lever locks with a fixed rivet installed in the metal strip running down the front of the knife like yours has are originals, and models with a screw in the strip are clones.
I am also under the impression that legitimate knives have brass liners whereas clones have steel liners.
Could you please post a close-up picture of the stamp on the tang?
I wouldn't be too concerned about centering, IMO it's over-rated, but that's me.
Regardless of the knife's validity it's a great fix-up you did, and now you have a solid knife to carry.
