The American company of Bausch & Lomb used to make some of the best scopes/mounts in the world, with the greatest optical integrity coming from their philosophy of wanting no reticle adjustments at all within the tube. They would not even cushion the lenses, like Lyman, for fear of cushioning eventually causing parallax after being compressed by recoil.
Unfortunately, their merger with Bushnell around 1970 was effectively a reverse takeover of the riflescope business, meaning the B&L outlook went out the window.
Hertel & Reuss, the company that swallowed Nickel, had originally grown out of some bankruptsy at Gerhard in the early 20th Century, according to Stroebel. This may have something to do with H&R being nominally taken back into Gerhard recently. That the name Nickel AG has been adopted for their most prestigious products is, I believe, a clue to the respect held for the old scopes made by B. Nickel at Marburg 50 years before. As you said, though, the people there seemed to know nothing about the history of the old firm, not even what the B. stood for.