Bonsa: Handles are cowhorn, Köller: Bone, I'd say ...
I don't think it's ivory, though I'm not absolutely sure. But since the logo on the blade +GF+ shows that this is an advertising giveaway from Georg Fischer GmbH I guess gifts are rarely made with ivory ... the etched letters are a monogram I'd say, maybe the owner's name was Christian Schmidt or Stefan Gruninger or whatever.
Age: 1960s seems to be an appropriate estimation; Böntgen&Sabin was shut down in 1970 (the Bonsa brand was then owned by Robert Klaas) - so 1970s could be plossible, too.